Natalie Grant Wraga, 101, who was born in czarist Russia, saw great upheaval in her native land and became an expert in unmasking Soviet deception methods for the State Department, died Nov. 12 at her home in Lovettsville. She had a heart ailment.

What distinguished Mrs. Wraga as a Sovietologist was her firsthand experience in imperialist Russia and the early Soviet state. As her peers died off, she became a rich and rare asset to the American intelligence community, to which she would often lecture about the origins of grand-scale deception.

Struck by her vivid speeches and scholarly writings, generations of Soviet-watchers visited her secluded, mountaintop home in Loudoun County. There, they would listen to the witness accounts from the small woman with bright blue eyes who was always impeccably dressed and had a fondness for chocolate croissants and raspberries.

Her father was a judge under the old czarist government, and she accompanied him through much of the country during his frequent job-related transfers from town to town. He and the family later left for the Crimea to escape the revolution of 1917.

Her life continued apace for the next few decades as she: dropped out of college because of civil unrest; married and divorced an American aid worker who landed in trouble with authorities; worked alongside diplomat George F. Kennan at the American legation in Riga, Latvia; married a high-ranking Polish intelligence official; was a political officer at the U.S. Embassy in Switzerland during World War II; and served as a Sovietologist at State in the 1950s and the Hoover Institution in California in the 1960s.

She then settled in the Washington area and wrote a book, "Window on Russia," about the formation of U.S. foreign policy toward Russia in the 1920s and 1930s.

"She was one of our leading authorities" on Soviet deceit, said Herbert Romerstein, a former staff member of the House Permanent Select Committee on Intelligence and director of the U.S. Information Agency's office to counter Soviet disinformation.

Romerstein said that Mrs. Wraga spoke on subjects ranging from the philosophical roots of Soviet deception to Soviet forgery techniques. She was particularly well versed in a Soviet operation called "the Trust" in the 1920s and 1930s, which conveyed false information to enemy intelligence services and anti-Stalin emigrants.

"Propaganda is obvious to anybody with any brains, but disinformation is not," she told John Berlau of Insight magazine. "Sometimes more than 90 percent of the content of disinformation is true. The thing that is important is to find the part that is false."

Sometimes it can be one word, she said.

Mrs. Wraga was born Natalia Konstantinovna Mark in what is now the Estonian capital Tallinn. She learned English and French from governesses, and her language proficiency helped her get a job with the American Relief Administration, a post-World War I relief effort. She met her first husband, Malcolm Grant, at the relief administration.

They were divorced, she told The Washington Post last year, after he was caught sending letters from Soviet citizens to their families abroad. He had to leave the country; she stayed.

In 1928, she joined the legation in Latvia, then the American "window on Russia" in the years before the United States formally recognized the Soviet Union. She was at the legation 11 years, studying Soviet documents and interviewing emigrants.

Mrs. Wraga had a begrudging respect for the Soviet Union's success at deception.

"One must give the Soviets their due," she wrote in Conservative Digest in 1990. "No other country is capable as are the Soviets of manipulating public opinion in the West. Only a year ago, Moscow was condemned for supporting terrorism. It was said to be involved in a terrorist attack against the Pope. Terrorists were statedly being trained under Soviet sponsorship.

"And, as if by magic, this murky Soviet image has now undergone a complete change," she added. "The Soviets have now become enemies of terror. With the help of some Americans who believe in this extraordinary transformation, Moscow now holds conferences and participates in talks on preventing terrorism."

Her second husband, Richard Wraga, died in 1968.

She leaves no immediate survivors.