WASHINGTON - Former national security adviser Samuel R. Berger, 70, who helped craft President Bill Clinton's foreign policy and got in trouble over destroying classified documents, died Wednesday after a battle with cancer.

Mr. Berger, who was known as Sandy, was national security adviser from 1997 to 2001, when the Clinton administration carried out airstrikes in Kosovo and against Saddam Hussein's forces in Iraq. Mr. Berger, a lawyer, also was deeply involved in the response to al-Qaeda's bombing of U.S. embassies in East Africa.

"Today, his legacy can be seen in a peaceful Balkans, our strong alliance with Japan, our deeper relationships with India and China," President Obama said in a statement.

In 2005, Mr. Berger pleaded guilty to removing classified documents from the National Archives by stuffing some papers in his pants leg. He cut up some of the documents with scissors, for reasons that remain unclear. He was sentenced to probation and a $50,000 fine. He expressed regret for his actions.

Out of government, he helped found an international consulting firm that in 2009 merged with one run by former Secretary of State Madeleine Albright.

Mr. Berger presided over foreign policy during what was a relatively serene period. The biggest trouble spot was the Balkans, where the breakup of Yugoslavia spawned a series of civil wars. The U.S. and its NATO allies took militarily action against what they viewed as Serbian aggression, first in the conflict over Bosnia and then in Kosovo.

He also played a key role in Operation Desert Fox, the four-day bombing of Iraq in 1998 over Hussein's failure to comply with U.N. weapons inspections.

Also in 1998, al-Qaeda attacked U.S. embassies in Kenya and Tanzania. The administration responded with a cruise missile barrage against training camps in Afghanistan and a pharmaceutical plant in Sudan. The strikes did little to disrupt al-Qaeda and became a thread in a long-running criticism that Clinton and his team failed to properly respond to a burgeoning terrorist threat.

But Mr. Berger was not blind to the problem. Briefing his Bush administration successor, Stephen Hadley, and incoming Secretary of State Condoleezza Rice in 2000, he said they would be "spending a lot of time dealing with al-Qaeda," Hadley recalled. "That was prophetic."

In court in 2005, Mr. Berger admitted to taking and destroying three copies of a classified report about the government's response to the millennium plot in 2000 by Islamic extremists to attack in Los Angeles and other locations. But a report by House Republicans said he may have removed many more documents from the Archives.

Mr. Berger, who grew up in Millerton, N.Y., met Bill Clinton while the two worked on George McGovern's 1972 presidential campaign.

"There is no one I have relied on more these past eight years," Clinton wrote Mr. Berger in a letter as the pair left office in January 2001. "You never flinched when American's interests and values demanded that we make unpopular choices."