Rejecting a prosecution request for a severe sentence, a panel of military officers on Thursday sentenced a former driver for Osama bin Laden convicted of a war crimes charge to five and a half years in prison. The sentence means that the first detainee convicted after a war crimes trial here could complete his punishment by the end of this year.

The military judge, Capt. Keith J. Allred of the Navy, had already said that he planned to give the driver, Salim Ahmed Hamdan, credit for at least the 61 months he has been held since being charged, out of more than six years in all. That would bring Hamdan to the end of his criminal sentence in five months. After that his fate is unclear, because the Bush administration says that it can hold detainees here until the end of the war on terror.

The unexpectedly short sentence came after Hamdan was acquitted on Wednesday of the most serious charge against him, conspiracy, having been convicted only of material support for terrorism. The extraordinary conclusion to the first of the post-Sept. 11 war crimes trials — a case that led to a landmark Supreme Court ruling in 2006 blocking a prior effort to prosecute him — once again raised many of the questions that have long surrounded the Bush administration’s military commission system here, which it plans to use to try another 80 detainees.

The sentence was far less than military prosecutors had sought. Through more than five years of proceedings, prosecutors had pursued a life sentence. Earlier in the day, faced with Hamdan’s acquittal on the most serious charge against him, the prosecutors recommended a sentence of at least 30 years and had said life might still be appropriate.

“Your sentence,” a prosecutor, John Murphy, told the panel, “should say the United States will hunt you down and give you a harsh but appropriate sentence if you provide material support for terrorism.”

Supporters of the military commission system and military prosecutors here said the sentence proved that the Bush administration’s system for trying detainees was legitimate and fair.

David Rivkin, a Washington lawyer who has been a consistent supporter of the administration’s detention policies, said it would be difficult for anyone to criticize the system after the sentence. “This is an enormously compelling indication of how independent the process has been,” Rivkin said.

The prosecutors said they would have preferred a longer sentence, but noted that they had won a conviction. “That’s the way a fair, open system works,” said one of the prosecutors, Maj. Omar Ashmawy. “The sentence isn’t always what the government asks for.”

Defense lawyers described the verdict as a victory propelled by the military officers on the panel, but they said it did not remedy what they have described as the system’s flaws.

“What ultimately happened, in spite of the system, was justice,” said Charles D. Swift, a former Navy lawyer who has forged a close relationship with Hamdan through more than five years of battles as his lawyer.

After just over an hour of deliberations on the sentence, the panel of six senior military officers returned to the windowless tribunal room with their sentence on the single war crimes charge on which they convicted him, providing material support to a terrorist organization.

For much of the past quarter century, the Chinese director Zhang Yimou made films that showcased his country’s struggle against poverty, war and political misrule to the outside world — films that Chinese, for the most part, never saw.

Time and again, Zhang’s terse, gritty epics were banned by government censors for portraying China’s ugly side. When he won an award at the Cannes Film Festival in 1994, the authorities stopped him from attending. Up for an Oscar one year, officials lobbied to have his film withdrawn from the competition.

But when the Olympics kick off Friday at China’s new National Stadium, with President Hu Jintao of China, President Bush and other world leaders in attendance and perhaps 1 billion people watching live on television, Zhang will preside over the opening ceremonies.

Nearly two years in the making, his spectacle is intended to present China’s new face to the world with stagecraft and pyrotechnics that organizers boast have no equal in the history of the games. Whether or not it succeeds, it will underscore one reality of a rising China: Many leading artists now work with, or at least not against, the ruling Communist Party.

Rising nationalism and pride in China’s emergence as an economic power, and robust state support for artists who steer clear of political defiance, have transformed China’s cultural landscape since the early part of this decade. Today, directors, writers and painters who seek to expose the darker side of authoritarian rule not only enrage the censors, but also often find themselves shut out of the lucrative market for Chinese art, books and film. Many of those who find less political outlets for their talent, on the other hand, can get rich.

“People really are selling their talent in a way that can make them money,” said Ai Weiwei, an internationally recognized artist based in Beijing. “They really know that if they work with the government, they’ll benefit.”

The opening ceremony will represent a particularly momentous conversion for Zhang, whose experience during the horrors of Mao’s Cultural Revolution appeared to inform several of his internationally acclaimed — and domestically banned — films, including “Ju Dou” and “To Live.”

Zhang said in a recent interview that he never had political aims. His supporters say it is the Communist Party that has become more sophisticated, seeking to harness the country’s top talent and embrace a broader notion of national culture.

In December 2002, federal investigators scoured an icy pond on a snow-covered mountain near Frederick, Md., hunting for clues that would lead to the anthrax killer.

As they worked, the Army microbiologist now believed to be responsible for the five deaths stood calmly in their midst, chatting, smiling and watching.

Bruce E. Ivins, the scientist and a Red Cross volunteer, mingled with the investigators in a military tent, serving coffee, doughnuts and chocolate bars to members of the Federal Bureau of Investigation and search teams.

Law enforcement officials hustled him away after they realized he was an anthrax researcher who could compromise the investigation, according to Red Cross volunteers who were there. Ivins seemed embarrassed by it all, prompting his friends to tease him about the incident.

Five years passed before the FBI turned its attention to the man who stood on the sidelines of the hunt that day. And Miriam Fleming, who was there as the divers plunged into the murky waters searching for evidence, said she still could not quite believe that the man identified as the anthrax killer was cheerfully working by her side.

“He was kind of goofy, but he was always in a good mood,” said Fleming, a Red Cross volunteer. “He seemed so normal.”

She added: “Now we have to figure it out: Who was the real Bruce Ivins?”

Last week, Ivins killed himself as the authorities were preparing to indict him in the mailing of the anthrax letters in 2001. Yet as his friends and colleagues note, Ivins was almost always in plain sight, offering assistance — and misleading information, officials say — to federal agents running the nation’s longest and most costly bioterrorism inquiry.

In the early days after the letter attacks in September and October 2001, Ivins joined about 90 colleagues at the Army Medical Research Institute of Infectious Diseases in a round-the-clock push to test thousands of samples of suspect powder to see if they were anthrax. He even helped to analyze a letter sent to former Sen. Tom Daschle, and went to the Pentagon to discuss the results.

Jeffrey Adamovicz, who was Ivins’ supervisor at the time, said he remembers the day the scientists opened that envelope, placed in a double-sealed bag inside a protective hood designed to deal with dangerous pathogens.

“The anthrax was floating around inside the bag,” Adamovicz said. “It was very scary.”

He said he turned to Ivins and said, “That stuff is amazing.”

“Yes, it is unbelievable,” he recalled Ivins replying. “I have never seen anything like that.”

Months later, as the FBI focused on the Army laboratory at Fort Detrick, Md., as a possible source of the anthrax, Ivins twice submitted samples from his own supplies that did not match the deadly spores used in the attack. Investigators later concluded he had chosen irrelevant samples to throw them off his trail.

A move by Pakistan’s usually fractious governing coalition on Thursday to impeach President Pervez Musharraf left the country on the brink of a political crisis that threatened to paralyze the government at a critical moment when the United States is demanding greater action against militants based here.

The governing coalition set no formal deadline for the start of impeachment proceedings against Musharraf, a favored U.S. ally, leaving open the possibility of a protracted and debilitating political fight that could take months of haggling to secure the parliamentary votes needed for impeachment. The actual charges have yet to be announced.

It also raised the threat that Musharraf would try to dissolve the Parliament, or that he would look to the army for protection, though many analysts said the military was unlikely to intervene. “The army preference is not to get involved and for the constitutional process to be followed so there is the least amount of disruption to the system,” said Shuja Nawaz, the author of Crossed Swords (Oxford University Press), a book on the Pakistani military. “They would not want to be drawn into it.”

The announcement that the civilian leaders would seek impeachment, made at a news conference here, was the culmination of months of wrenching political changes after the assassination of the opposition leader Benazir Bhutto in December and the decisive victory of her party in elections in February. Since then, the leaders of the country’s two major parties, Asif Ali Zardari and Nawaz Sharif, have forged a tense governing coalition that has teetered on collapse.

Zardari, the head of the Pakistan Peoples Party, and Sharif, the leader of the Pakistan Muslim League-N, have barely been on speaking terms. For the last several days, they were closeted in meetings on how to keep their fractious coalition together.

Sharif, who was ousted as prime minister by Musharraf in the 1999 coup, has been pushing Zardari to join impeachment proceedings against the president. Zardari had been resisting, but this week he apparently decided that the one way to keep the coalition functioning was to undertake a frontal attack on Musharraf, who is immensely unpopular, after having ruled Pakistan as a military leader for eight years until late 2007.

On Thursday, the two coalition leaders issued a joint communique saying their government would “immediately initiate impeachment proceedings” and that it would “present a charge sheet against General Musharraf.”

Musharraf was described by his allies as determined to fight back, and met all day on Thursday with his political backers and his constitutional lawyer, Syed Sharifuddin Pirzada. In an indication of the gravity of his situation, the president called off his trip to attend the opening of the Olympic Games.

Many Pakistani officials said they believed Musharraf would seek support from the Bush administration. It has endowed Pakistan with more than $12 billion of mostly military aid since 9/11 for its cooperation in combating the insurgency of the Taliban and al-Qaida that is washing over the border into Afghanistan and conducting attacks on U.S. troops there.

Fighting in the border region between the former Soviet republic of Georgia and a breakaway Georgian enclave has reached its highest level in years, with Georgia saying that up to 10 civilians and soldiers had been killed in violence that erupted overnight on Wednesday and lasted throughout the day on Thursday.

The deaths were part of an intense, new round of fighting that has continued sporadically since last Saturday, when six people in South Ossetia, the breakaway enclave, died and more than 20 were wounded on both sides.

South Ossetia has reported evacuating women, children and the elderly from the conflict zone, sending them north into Russia, while news agencies reported heavy fire around the enclave’s capital, Tskhinvali, early Friday morning.

The recent violence has been the worst to hit the region since June 2004, shortly after President Mikheil Saakashvili of Georgia came to power vowing to reassert the country’s control over South Ossetia and another rebel region, Abkhazia.

The two separatist republics are internationally unrecognized but gained de facto independence from Georgia after a series of bloody wars in the 1990s during which thousands died. The republics then settled into a period of tenuous peace monitored by a contingent of Russian peacekeeping troops.

Upon taking power, Saakashvili challenged Russian preeminence in the region by seeking NATO membership and deeper ties with the West. His government has accused Russia of training and supplying separatist forces in both South Ossetia and Abkhazia under the auspices of its peacekeeping mission — accusations that Moscow denies.

Tensions further escalated earlier this year when Kosovo declared its independence from Serbia in February and was subsequently recognized by several Western countries. Russia, an ally of Serbia, had vehemently opposed the move and vowed to increase its support for Abkhazia and South Ossetia — a poor, mountainous territory between Georgia and Russia’s southern border — in retaliation.

Georgia and South Ossetia blame one another for starting the current violence, and it is still unclear whether the fighting could intensify into full-scale war or simply peter out as have past skirmishes in this long-running conflict.

“It does give off the appearance that the violence is linked to strategic moves by one or both sides to improve their positions,” said Ana Jelenkovic, an associate at the Eurasia Group.

In the violence this week, separatist fighters from South Ossetia, the breakaway enclave, used rocket-propelled grenades to blow up a Georgian armored personnel carrier, killing two soldiers and injuring six others, Shota Utiashvili, a Georgian interior ministry spokesman said. Up to eight Georgian civilians were killed in a separate mortar attack on Thursday on the village of Avnevi in the border region, he said.

The Environmental Protection Agency rejected on Thursday a request to cut the federal government’s quota for the use of ethanol in cars, concluding, at least for now, that the national goal of reducing oil use trumps any effect on food prices from making fuel from corn.

The agency’s administrator, Stephen L. Johnson, said the mandate was “strengthening our nation’s energy security and supporting American farming communities,” and that the mandate was not causing “severe harm to the economy or the environment.”

The effect of the decision on fuel and food markets is hard to predict. Farmers argued that the jump in corn prices was driven not so much by the demand for ethanol as by growing demand for grain-fed meat around the world and by their own higher costs for diesel fuel.

Recently, high oil prices have led to even more ethanol production than the quota required. On the other hand, rising corn prices made some ethanol operations unprofitable, especially as oil prices started to fall.

Sen. John McCain’s presidential campaign said Thursday that it would return all the contributions solicited for it by the Jordanian business partner of a prominent Florida fundraiser for McCain.

For the McCain camp, the decision caps a queasy two days in which news accounts scrutinized a cluster of more than $50,000 in unusual contributions from a single extended family of Californians, the Abdullahs, and several of their friends.

The bundling of the donations was initially credited by the campaign to Harry Sargeant III, finance chairman of the Florida Republican Party and part-owner of a major oil trading company. But they were actually solicited by Mustafa Abu Naba’a, a longtime business partner of Sargeant.

The donations came under scrutiny because of their large size and the fact that for the most part, the Abdullahs do not appear wealthy. In addition, several of them interviewed expressed indifference or even hostility to McCain’s candidacy.

President Bush toured Bangkok’s fetid slums, lunched with Burmese dissidents and delivered a speech critical of China to a carefully screened crowd here on Thursday, using them as backdrops for his message on human rights and democracy during his final tour of Asia.

With the first lady, Laura Bush, visiting a Burmese refugee camp packed with thousands of anxious families, the president railed against what he called the tyranny in Myanmar, chided China for its lack of religious freedom and praised Thailand as “the land of the free.”

“The passion for liberty transcends culture and faith,” Bush told a handpicked, polite group of Thai politicians, university students and other dignitaries.

The selection of Thailand for what the administration billed as a major policy speech partly reflected the country’s longstanding ties with the United States, cemented by the Vietnam War, when American soldiers used Thailand as a staging ground.

But Bangkok was also an awkward location for a speech about human rights and democracy given Thailand’s military coup two years ago and its continuing political instability.

Americans sought out more bargains and cheaper goods in July, leaving the nation’s biggest retailers bracing for a painful back-to-school shopping season.

Retail sales reports released Thursday revealed a country that is rapidly ratcheting back its spending habits, and abandoning midtier and discount shopping mall mainstays that were booming a year ago.

The biggest surprise was a middling month for Wal-Mart Stores, the behemoth of the discount retail industry, which reported an increase in sales but missed Wall Street’s estimates. Wal-Mart also warned that its sales would slow in August, as the stimulus from the government’s tax rebates fades away.

The gloomy forecast helped depress stocks on Thursday, and the Dow Jones industrials were down about 120 points at mid-day. Wal-Mart shares tumbled more than 4 percent.

For months, sales at the big retail stores have been closely tracked as a gauge of trends in consumer spending, which accounts for more than two-thirds of the nation’s economic growth. Retailers showed some resilience, with many stores beating sales estimates, in part, because of the government’s tax rebates.

But as the stimulus program winds down, few buffers will separate retailers from consumers struggling with higher fuel and food prices, a housing price collapse and a tight credit market.

The European Central Bank left its benchmark interest rate unchanged on Thursday amid mounting evidence that the economy of the 15-nation euro area was slowing.

The bank kept its rate at 4.25 percent after it bucked the trend of major central banks in July by raising its rate a quarter percentage point, a step aimed at cooling expectations of rising inflation.

On Thursday, the Bank of England also kept its key rate unchanged at 5 percent, as it sought to balance its twin goals of keeping inflation under control while mitigating the worst effects of a significant slowdown in the British economy.

The European bank is holding rates steady amid increasing evidence that the Continent’s economy appears to have slowed dramatically in the last few months, a development that reflects a much weaker outlook in Germany, which accounts for a third of the region’s output.

German industrial orders, the backbone of its growth, fell 2.9 percent in June from May, the seventh consecutive decline, according to data released Wednesday. Orders from the rest of the euro area, Germany’s largest market, declined 7.7 percent in the same period.

“German manufacturers clearly can’t escape unscathed from the darkening outlook for the global economy,” Alexander Koch, an economist at UniCredit, wrote in a research note.

A terrorist group seeking an independent Muslim state in western China has released a video threatening an attack on the Olympic Games here, according to an American organization that tracks terrorist Internet posts.

The video’s opening graphics show a burning Olympic logo and an explosion superimposed over one of the athletic sites, said the monitoring organization, IntelCenter, based in Alexandria, Va.

According to IntelCenter’s description, a man holding a Kalashnikov rifle, who identifies himself as Abdullah Mansour, says in the Uighur language: “We, members of the Turkestan Islamic Party, have declared war against China. We oppose China’s occupation of our homeland of East Turkestan, which is a part of the Islamic world.”

He warns Muslims not to go to the games and not to let their children go. “We do not want to see any Muslim brothers and sisters who believe in Allah and his Holy Prophet Muhammad, who believe in the next life and the day of judgment, get hurt by our fire targeted at China,” he says.

The Uighurs, a Turkic Muslim people, dominate the Xinjiang region in western China.

The video’s violent opening graphics are the same as those in a video the group released July 23, in which it claimed responsibility for bus bombings in Kunming and Shanghai that killed five people and wounded at least 26. In that video, a masked spokesman threatened violence against the Olympics.

With a new analytical technique, a fingerprint can now reveal much more than the identity of a person. It can now also identify what the person has been touching drugs, explosives or poisons, for example.

Writing in Friday’s issue of the journal Science, Dr. R. Graham Cooks, a professor of chemistry at Purdue University, and his colleagues describe how a laboratory technique, mass spectrometry, could find a wider application in crime investigations.

The equipment to perform such tests is already commercially available, although prohibitively expensive for all but the largest crime laboratories. Smaller, cheaper, portable versions of such analyzers are probably only a couple of years away.

In Cooks’ method, a tiny spray of liquid that has been electrically charged — either water or water and alcohol — is sprayed on a tiny bit of the fingerprint. The droplets dissolve compounds in the fingerprints and splash them off the surface into the analyzer. The liquid is heated and evaporates, and the electrical charge is transferred to the fingerprint molecules, which are then identified by a device called a mass spectrometer. The process is repeated over the entire fingerprint, producing a two-dimensional image.

Those without air conditioning may rejoice — high temperatures for this weekend and next week look to remain near or below the average high of 80°F for this time of year. Today, the wind continues to blow from the east, bringing cold air from above the ocean. Temperatures will top out in the low 70s, accompanied by clouds and a chance for more thunderstorms. Saturday looks to be quite pleasant, as winds change to westerly and we get the warmer inland air. We should finally get some sunshine, as well as lower dew points (the dew point is a measure of the absolute moisture content of the air). The chance for thunderstorms returns Sunday night, with a chance of showers each day next week.

For the remainder of the month, look towards the southern sky just after dark. The planet Jupiter will appear as a bright star about 30° above the horizon.

Federal policymakers have concluded that the turmoil plaguing the housing and financial markets is likely to spill deep into 2009, becoming one of the most significant domestic problems to confront the next president when he steps into the Oval Office in January.

Ben S. Bernanke, the chairman of the Federal Reserve, publicly indicated on Tuesday that he believes the problems will persist into next year when he outlined a series of steps the Fed is considering in the coming months.

One such step would extend low-interest lending programs to Wall Street’s largest investment banks into next year. The programs, one of which was set to expire in September, can continue only if the Fed issues a finding that there are “unusual and exigent circumstances” that justify them.

Bernanke also recommended that Congress grant the Fed broader authority to monitor and supervise the financial markets to assure greater stability in the future. But with time running out on this session, lawmakers are unlikely to adopt such legislation before next year.

Treasury Secretary Henry M. Paulson Jr. said in a speech last week in London that the problems plaguing the housing and financial markets might last longer than originally expected.

He followed up in another speech on Tuesday by saying that the Bush administration was working to prevent as many home foreclosures as possible, but that “many of today’s unusually high number of foreclosures are not preventable.” Paulson said 1.5 million home foreclosures were started in 2007 and that an estimated 2.5 million more would take place this year.

Still, the markets seemed reassured that Washington officials were redoubling their efforts to resuscitate the weak housing sector, despite the downbeat comments. The Dow Jones industrial average closed, which has fallen sharply in recent weeks, closed up 1.4 percent, or 152 points.

Bernanke said that the Fed would issue next week long-awaited rules to restrict new exotic mortgages and high-cost loans for people with weak credit. Such mortgages have been a central cause of the current market problems.

The Federal Housing Administration will also begin an expanded effort next week to help a larger group of troubled homeowners refinance their adjustable mortgages. Under the plan, homeowners would be eligible to refinance even if they have missed up to three monthly mortgage payments over the previous 12 months. Homeowners who have fallen behind on their payments because of job loss, declining wages and family illness will also be eligible, even if their rates have not increased. Homeowners are now eligible only if they were current on their mortgages before their interest rate was adjusted upward.

For its part, Congress is close to completing legislation on a $300 billion foreclosure-rescue plan that would help troubled borrowers refinance into more affordable loans insured by the federal government. The Senate is expected to approve a measure by next week.

The Fed created the lending programs to Wall Street in March as part of a broader effort to prevent financial institutions from collapsing, as Bear Stearns nearly did before it was sold under heavy pressure from the Fed and the Bush administration to JPMorgan Chase.

President Bush and leaders of the world’s richest nations pledged Tuesday to “move toward a low-carbon society” by cutting greenhouse gas emissions in half by 2050, the latest step in a long evolution by a president who for years played down the threat of global warming.

The declaration by the Group of Eight — the United States, Japan, Germany, Britain, France, Italy, Canada and Russia — was the first time that the Bush White House had publicly backed an explicit long-term target for eliminating the gases that scientists have said are warming the planet. But it failed to set a similar goal for cutting emissions over the next decade, and drew sharp criticism from environmentalists, who called it a missed opportunity.

In a sense, the document represents an environmental quid pro quo. In exchange for agreeing to the “50 by 2050” language, Bush got what he has sought as his price for joining an international accord: a statement from the rest of the Group of Eight that developing nations like China and India, which have declined to accept mandatory caps on carbon emissions, must be included in any climate change treaty.

European leaders, who have long pressed Bush to take a more aggressive stance on global warming, said the declaration could enhance efforts to reach a binding agreement to reduce emissions when negotiators meet in Copenhagen, Denmark, next year under U.N. auspices.

“This is a strong signal to citizens around the world,” the president of the European Commission, Jose Manuel Barroso, told reporters at a news conference near here. “The science is clear; the economic case for action is stronger than ever. Now we need to go the extra mile to secure an ambitious global deal in Copenhagen.”

The leaders of the eight industrialized countries, who gathered on the northern Japanese island of Hokkaido for their annual meeting, spent months debating the language of Tuesday’s communique in lower-level negotiations. Critics said it was short on specifics, and that both developed and developing countries would need to make much sharper cuts in emissions to head off the worst effects of global warming.

The statement left unclear, for instance, whether the cuts made by 2050 would be pegged to current emissions levels, or 1990 levels, as many advocates had hoped.

The United States and the Czech Republic signed a landmark accord on Tuesday to allow the Pentagon to deploy part of its widely debated anti-ballistic missile shield on territory once occupied by Soviet troops.

The accord, the first of its kind to be reached with a Central or East European country, was signed in Prague by Secretary of State Condoleezza Rice and her Czech counterpart, Karel Schwarzenberg, despite strong opposition from Russia. It must also be ratified by Czech lawmakers, many of whom oppose it.

Russia warned on Tuesday that the accord could lead to a military response, which the Kremlin has previously threatened but never specified.

President Dmitri A. Medvedev and his predecessor, Vladimir V. Putin, who is now the Russian prime minister, had told the United States that the Kremlin saw a missile shield in this part of Europe as a threat to Russian security. Putin said it could even lead to a new Cold War.

But American and Czech officials said the system’s radar component, to be stationed south of Prague, would defend the NATO members in Europe and the United States against long-range weapons from the Middle East, particularly Iran.

“Ballistic missile proliferation is not an imaginary threat,” Rice said Tuesday after meeting with the Czech prime minister, Mirek Topolanek. She said Iran continued to work toward a nuclear bomb, along with long-range missiles that could carry a warhead.

Rice is on a European tour that includes Bulgaria and Georgia, but not Poland. The United States hopes to base 10 interceptor missiles there, but the governments in Warsaw and Washington have so far failed to reach agreement on the terms.

Unlike the Czech Republic, the Polish center-right government led by Donald Tusk has taken a tough negotiating stance. In return for hosting the interceptors, Poland has asked the United States to modernize Polish air defenses so that the country can defend itself against incoming short-range and medium-range missiles.

The accord with the Czech Republic is not without its problems.

The deal signed on Tuesday does not ensure that the radar system will be built immediately or that the next American administration will stick to the project.

Negotiations are still taking place on a second treaty that deals with the legal status of American troops to be deployed at the planned radar base. Both treaties must be ratified by Czech legislators, many of whom are skeptical about the project, while the public is largely opposed.

Topolanek’s coalition government does not have enough seats to assure support for the plans and may need opposition votes. Legislators from the Green Party, the government’s junior coalition partner, have indicated they may block the proposals, and opposition parties have demanded a national referendum. About two-thirds of Czechs oppose the radar deployment, according to opinion polls.

“Ratification will be difficult,” said Jiri Schneider, program director at the Prague Security Studies Institute. “The missile defense plan has sparked a national debate about how exposed we want to be on the international stage.”

With a month remaining before the Beijing Olympics, the International Olympic Committee on Tuesday praised the city’s preparations but also cited two “open issues” that remain: whether the city can deliver good air quality and fulfill promises to allow television networks to broadcast from non-Olympic sites.

“We think we’ve done everything,” said Hein Verbruggen, chairman of the IOC’s Coordination Commission, in a telephone interview. “But now we have to see in practice how it will work.”

Pollution and media access remain uncertainties as Beijing hustles to finish construction projects, plant flowers and get the city ready for the Aug. 8 opening ceremonies. On Tuesday, Beijing organizers christened the two state-of-the-art Olympic media centers that will house more than 20,000 journalists during the games.

The controversy over broadcast access began in March, after the authorities suppressed the violent Tibetan protests in western China. Beijing announced that networks would not be allowed to broadcast live from Tiananmen Square. The square is the symbolic center of Beijing and offers striking views of the Forbidden City. But it is also where Chinese troops crushed pro-democracy protesters in 1989 and is still a magnet for occasional protesters.

Verbruggen, who led a 12-member IOC delegation in Beijing this week, said the issue of broadcast rights from the Forbidden City, the Great Wall of China and other “icon” destinations was discussed during meetings Monday and Tuesday with the Beijing Olympic Games Organizing Committee.

“There will be a lot of opportunities to use all the icons,” Verbruggen said. He said networks would face restrictions on when they were permitted to televise from Tiananmen Square, but that local authorities had “granted it will be possible to film there.”

Last year, Beijing lifted certain domestic travel restrictions on foreign journalists as part of its Olympic pledge to allow more open media coverage. But foreign journalists have continued to experience sporadic interference, especially after the Tibet crisis. Foreign journalists are still blocked from traveling to certain Tibetan areas in western China. On Monday, Human Rights Watch released a report accusing China of failing to fulfill its promises on media freedom.

Now, television networks want assurances that Beijing will follow through on its pledges to allow live shots at non-Olympic venues. Last week, members of a German ZDF television crew said they were harassed by plainclothes and uniformed security officers as they tried to film live shots from the Great Wall of China — even though the crew had government approval. Security officers jumped in front of the cameras during live shots and some Chinese citizens interviewed by the crew were later questioned by authorities, according to the Foreign Correspondent’s Club of China.

Executives at some American television networks privately acknowledge problems securing broadcasting access in Beijing. Some stations that reserved locations for live shots later had their permissions revoked

Oil prices headed in an unusual direction — down — for the second consecutive day on Tuesday, leaving energy experts to wonder whether the drop is the beginning of a lasting trend or just a brief pause before another surge.

Oil settled at $136.04 a barrel, a drop of $5.33, or 3.8 percent. Analysts said the immediate causes included the strengthening of the dollar in recent days and the apparent veering northward of Bertha, the first hurricane of the 2008 hurricane season, meaning it was likely to miss the oil and natural gas facilities in the Gulf of Mexico.

They also noted that President Mahmoud Ahmadinejad of Iran had dismissed the possibility that war with the United States and Israel was imminent in remarks to reporters in Kuala Lumpur, Malaysia, relieving worries that Iran might try to block oil shipments in the Strait of Hormuz.

The decline bolstered a rally in the stock market, with the Dow Jones industrial average rising 152.25 points, or 1.36 percent, to 11,384.21. The broader Standard & Poor’s 500-stock index ended up 1.71 percent, and the Nasdaq composite climbed 2.28 percent.

But even as a barrel of oil lost more than 6 percent of its value since the Fourth of July weekend, energy analysts warned that it was too soon to predict an outright collapse in prices. Some predicted that this was just one more in a series of pauses that has accompanied the volatile rise in oil prices from $60 last summer and just below $100 at the beginning of the year.

Others were just left bewildered.

Chip Johnson, the president and chief executive of Carrizo Oil and Gas, a Houston-based company, said he was “confused” by “such wild swings.” But he added: “I can’t see oil getting cheap again ever. It’s just too hard to find, and too many people want to use it.”

Any sustained decline in oil prices could help the consumer at a time when higher food and energy prices have forced many to cut back spending on other goods. It could also help the ailing automotive and airline industries, lower the trade deficit and strengthen the dollar. Prices for gold, silver, copper and corn also dropped on Tuesday.

But the factors bringing down oil prices over the last two days could be short-lived. Traders have been using oil as a hedge against the dollar in recent years, and there is no assurance the dollar will strengthen for long if the economy further weakens. Another hurricane could develop at any time, and the strongest normally come in August and September. Tensions in the Middle East, Nigeria and other oil-producing areas can always erupt to put pressure on tight reserves.

“I don’t think there has been any change in the overall direction of the oil market,” said Addison Armstrong, director of market research at Tradition Energy, an energy broker that deals with banks and hedge funds. “The bias is still clearly to the upside, with $150 firmly in the sights of traders.”

A senior Iranian official was quoted Tuesday as threatening that Iran would respond to any military attack by striking Israel and America’s vital interests around the globe.

“In case that they commit such foolishness, Tel Aviv and the U.S. fleet in the Persian Gulf would be the first targets to burst into flames receiving Iran’s crushing response,” said Ali Shirazi, a representative of Ayatollah Ali Khamenei, Iran’s supreme leader, according to the ISNA news agency.

The threat — which drew no immediate response from Israel or the United States — was the latest salvo in the complex maneuvering around Western efforts to persuade Iran to abandon its nuclear ambitions, particularly the enrichment of uranium.

The United States, Israel and other Western countries fear that Iran’s nuclear program is designed to build nuclear weapons, but Tehran says it is for civilian purposes.

Congressional investigators said Tuesday that Medicare had paid tens of millions of dollars to suppliers improperly using identification numbers of doctors who died years ago.

The government has no reliable way to spot claims linked to dead doctors, many of whom are still listed as active Medicare providers though they died 10 or 15 years ago, the Senate Permanent Subcommittee on Investigations said.

Medicare covers wheelchairs, walkers, home oxygen equipment and many other types of medical equipment. When suppliers file claims for equipment provided to a Medicare beneficiary, they normally must list an identification number for the doctor who prescribed or ordered it.

“From 2000 to 2007, Medicare paid 478,500 claims containing identification numbers that were assigned to deceased physicians,” the subcommittee said in a new report. “The total amount paid for these claims is estimated to be between $60 million and $92 million. These claims contained identification numbers for an estimated 16,548 to 18,240 deceased physicians.”

Iraqi officials continued to insist Tuesday that a timetable for the withdrawal of coalition troops must be included in any security agreement with the United States.

Meanwhile, in western Anbar province, 22 bodies were found at a Ramadi elementary school that was undergoing construction, 20 of them buried in the playing fields, apparently over a lengthy period, the local police said.

Mowaffak al-Rubaie, the national security adviser, said the government would reject any security agreement that did not include a schedule for the departure of foreign troops.

“We will not accept a memorandum of understanding without having timeline horizons for the cessation of combat operations as well as the departure of all the combat brigades,” al-Rubaie said in a telephone interview. However, he declined to offer specifics on a timeline, suggesting that the Iraqi government itself was not yet sure how quickly it wanted the United States to withdraw.

Earlier in the day, al-Rubaie was in the holy city of Najaf meeting with Grand Ayatollah Ali al-Sistani, Iraq’s most senior Shiite religious leader. The ayatollah has not expressed an opinion on the specifics of the negotiations, emphasizing only that Iraq must protect its sovereignty.

The suicide bombing on Monday outside the Indian Embassy in Kabul was the latest and most audacious attack in recent months on Indian interests in Afghanistan, where New Delhi, since helping to topple the Taliban in 2001, has staked its largest outside aid package ever.

India has poured unprecedented amounts of money and people into the reconstruction of Afghanistan, a vital passage into resource-rich Central Asia. It has spent more than $750 million, building a strategic road across the country’s southwest, training teachers and civil servants, and working on erecting a new seat of the national Parliament.

That engagement has come at a mounting cost to the 4,000 Indian citizens working in Afghanistan. In the last two and a half years, an Indian driver for the road reconstruction team was found decapitated, an engineer was abducted and killed, and seven members of the paramilitary force guarding Indian reconstruction crews were slain.

Last year alone, the Indian Border Roads Organization came under 30 rocket attacks as it built the 124-mile stretch of road across Nimroz province that will ultimately link landlocked Afghanistan to a seaport in Iran.

The embassy bombing on Monday seems to have been the most effective strike: A suicide bomber blew himself up as two Indian diplomats drove into the embassy early in the morning, reducing the compound to rubble and blood. Four Indians, including the two diplomats, were killed. The bulk of the 41 dead were Afghan civilians who had come for embassy services.

President Nicolas Sarkozy of France, who is expected to announce on Wednesday that he will after all attend the opening ceremonies of Beijing’s Olympic Games, was warned by China on Tuesday not to meet with the Dalai Lama in France next month.

China’s ambassador to France, Kong Quan, told reporters there would be “serious consequences” for Chinese-French relations if Sarkozy meets the Dalai Lama, asserting that it “would be contrary to the principle of noninterference in internal affairs.”

Sarkozy has been vague on whether he would meet personally with the Dalai Lama, the spiritual leader-in-exile of Tibet, regarded by China as a renegade “splittist” who has advocated resistance to China’s sovereignty.

China has repeatedly blamed the Dalai Lama and his subordinates for instigating anti-Chinese riots in Tibet three months ago and encouraging a boycott of the Beijing Olympics, which the Dalai Lama has denied. Representatives of both sides recently resumed suspended reconciliation talks.

France holds the presidency of the European Union, and Sarkozy has said that his attendance at the Aug. 8 opening ceremonies will depend on progress in those talks. The Dalai Lama’s visit to France, for a conference on Buddhism, comes after the opening of the Olympics.

Two former secretaries of state, concluding that a 1973 measure limiting the president’s ability to wage war unilaterally had never worked as intended, proposed on Tuesday a new system of closer consultation between the White House and Congress before U.S. forces go into battle.

Their proposal would require the president to consult senior lawmakers before initiating combat expected to last longer than a week, except for covert operations or rare cases requiring emergency action, in which case consultation would have to be undertaken within three days. Congress would have 30 days to approve the military action or, if it declined to do so, could then order it ended by disapproving it.

The plan would create a new committee of congressional leaders and relevant committee chairmen, with a full-time staff that would have access to military and intelligence material. The president would be required to consult with the group in advance of any major strike and regularly throughout any extended conflict.

The two former secretaries of state, Warren Christopher and James A. Baker III, oversaw a year-long bipartisan study of the tension over war powers that has vexed the U.S. government since its founding. In a report released on Tuesday, the study group concluded that the 1973 law, which is known as the War Powers Resolution and was adopted in the wake of U.S. involvement in the Vietnam War, was lacking in a number of regards.

The United States and other regional powers will resume talks with North Korea this week on ending the Communist state’s nuclear weapons programs, a South Korean envoy said Tuesday.

The six-nation talks, the first in nine months, are to begin on Thursday, the South Korean envoy, Kim Sook, told reporters before flying to Beijing for the conference among the United States, the two Koreas, China, Japan and Russia.

A deadlock was broken late last month when North Korea submitted a long-delayed but partial account of its nuclear programs and the United States moved to take North Korea off its terrorism blacklist and relax some economic sanctions.

Kim said the new talks would l focus on verifying the North’s nuclear account, including the amount of plutonium the North has reported. But the envoys will also discuss speeding up the disabling of North Korea’s main nuclear complex in return for fuel aid shipments.

North Korea has delayed removing spent fuel rods — a source of plutonium — from its main nuclear reactor while complaining that the other five nations had not provided the promised fuel aid in a timely fashion.