Washington ? The Supreme Court said Monday that victims of Nazi-era plundering can use U.S. courts to try to get their belongings back, handing a California woman a narrow but important victory in her bid to reclaim expensive paintings from Austria.

The justices, in a 6-3 ruling, said it didn’t matter that Congress failed to hold foreign governments liable for their conduct until 1976, because lawmakers intended for the Foreign Sovereign Immunities Act to be applied retroactively. But the court cautioned that the governments of Austria and the United States still could raise obstacles to Maria Altmann’s quest to have family treasures returned.

Justice John Paul Stevens, writing for the majority, noted the “narrowness” of the ruling, and pointed out that both governments have formidable arguments that must be dealt with at trial. He was joined by Justices Stephen Breyer, Ruth Bader Ginsburg, David Souter, Sandra Day O’Connor and Antonin Scalia.

In his dissent, Justice Anthony Kennedy worried that the court had ignored an important rule against the retroactivity of laws, and had injected “great prospective uncertainty into our relations with foreign sovereigns.” He was joined by Chief Justice William Rehnquist and Justice Clarence Thomas.

The decision means that Altmann, an 87-year-old who fled Austria and settled in California, will be able to go ahead with her suit.

It gives new hope to a proliferating number of claims against governments that engaged in World War II-era misconduct: A group of Asian women is suing Japan for the mistreatment they endured as “comfort women” who served as sex slaves for Japanese soldiers. A group of Holocaust survivors is suing the French national railroad for its role in transporting Jews to concentration camps during the war.

Mexican trucks

Also Monday, the court cleared the way for thousands of Mexican trucks and buses to begin delivering goods and passengers throughout the United States, ending a decadelong dispute that pitted environmentalists against NAFTA and became a sore point in U.S.-Mexico relations.

Siding with President Bush, the justices, ruling 9-0, threw out a court order that had blocked the free flow of Mexican trucks on the grounds that the often older diesel-burning vehicles would belch more dirty air in already polluted areas of the Southwest.

Last year, the 9th U.S. Circuit Court of Appeals in California said the nation’s anti-pollution laws required U.S. officials to study the effect on the environment before opening the borders to older trucks from Mexico.

But the Supreme Court set aside that ruling Monday and said the president has the power to enforce the North American Free Trade Agreement.

“Because the president, not (the motor vehicle regulators), could authorize cross-border operations from Mexican motor carriers, (the chief executive) did not need to consider the environmental effects arising from the entry,” said Thomas in a narrow ruling by the court.