Walter Laqueur, shown here in 1981, died Sept. 30 at 97. (Fred Sweets/The Washington Post)

Walter Laqueur, a German Jew who fled Adolf Hitler and became one of the preeminent intellectuals of his generation, with seminal books dissecting events that shaped the 20th century as well as his own life, died Sept. 30 at his home in Washington. He was 97.

His wife, Susi Laqueur, confirmed the death and said she did not yet know the cause. Mr. Laqueur, who wrote about Nazi Europe, the Soviet Union, Israel and the history of terrorism, was a former professor at Georgetown University and chairman of the International Research Council of the Center for Strategic and International Studies in Washington.

Mr. Laqueur grew up in Bres­lau, Germany, in a modest home that he remembered as adorned by geraniums. He was 17 in 1938 when he left Germany days before the Nazi-led Kristallnacht pogroms and, on his own, made his way to what was then the British mandate of Palestine, where he was granted entry as a student.

His mother and father, who remained in Europe and ultimately died in the Holocaust, bade him a tear-soaked goodbye at the train station. Years later, Mr. Laqueur searched his memory to recall, “When did I hear the last time from my parents?” — a scholar’s struggle to understand his personal losses through the world events that caused them.

But if he dwelled on the past, it was only in historical studies that invariably carried relevance for the present and future. Bruce Hoffman, a terrorism specialist and colleague of Mr. Laqueur at Georgetown, credited Mr. Laqueur with turning an “enormously inquiring and skeptical mind” to the watersheds of modern history.

Among his most noted works were the classic volumes “A History of Zionism” (1972) and “A History of Terrorism” (1977), which Hoffman described as the first major effort to move beyond journalistic, anecdotal or polemical discussions of terrorism to understand its deepest roots. Peter Bergen, a journalist and authority on Osama bin Laden, has called Mr. Laqueur the “dean of terrorism studies.”

In prolific writings on Russia, Mr. Laqueur predicted the brand of authoritarianism that Vladi­mir Putin would bring to the country, where other Kremlin watchers had harbored hopes for democracy after the collapse of the Soviet Union.

As a Holocaust survivor, Hoffman said, Mr. Laqueur experienced the “worst and the best of mankind.” Although he nurtured an “abiding faith in the power of democracy,” Hoffman observed, he was primed to see “emerging threats to civil society and to the liberal democratic state,” particularly where Europe was concerned.

Mr. Laqueur spoke of the “shattered heritage” bequeathed to his generation by World War II and became known, in the description of the Economist magazine, as “a leading prophet of European decline.”

He analyzed challenges facing the continent, among them a demographic crisis, a stalled spirit of competitiveness and an influx of Muslim immigrants. Among his recent titles on those topics were “The Last Days of Europe: Epitaph for an Old Continent” (2007) and “After the Fall: The End of the European Dream and the Decline of a Continent” (2011).

“Europe will not be buried by ashes, like Pompeii or Herculaneum, but Europe is in decline,” he told the German publication Der Spiegel in 2013. “It’s certainly horrifying to consider its helplessness in the face of the approaching storms. After being the center of world politics for so long, the old continent now runs the risk of becoming a pawn.”

He evinced perhaps even less hope for Russia. His views were informed by travels with his wife to see her family in what was then the Soviet Union, where he established contacts at a time when relatively few scholars visited the Communist nation.

“He had a deep knowledge of the Soviet Union and of Russian history, and understanding the patterns of what had happened in Russian history over the century would make one pretty skeptical about what might happen” after the Soviet Union broke up, Angela Stent, a Russian specialist at Georgetown, said in an interview.

In addition to noted books about Russia and its relationship with Germany and with the Middle East, Mr. Laqueur wrote “Black Hundred: The Rise of the Extreme Right in Russia” (1993), in which he foretold that “an authoritarian system based on some nationalist populism appears more probable” than democracy, and “Putinism: Russia and Its Future With the West” (2015), published the year Mr. Laqueur turned 94.

Mr. Laqueur often broke with conventional wisdom, nowhere more than in his writings on terrorism. He was credited with debunking myths often repeated by politicians, such as a purported link between poverty and terrorism.

“In the forty-nine countries currently designated by the United Nations as the least developed, hardly any terrorist activity occurs,” he noted in his book “No End to War: Terrorism in the Twenty-First Century” (2003). The presence of aggression and fanaticism, he wrote, were far greater predictors.

Mr. Laqueur wrote that “terrorism is relatively cheap and will be with us as long as anyone can envision, even if not always at the same frequency and intensity.” The statement might have made him look the part of a pessimist. But in rational pessimism lay a certain faith in the future. Only pessimists survived the Holocaust, Hoffman recalled Mr. Laqueur saying, because optimists believed Hitler could be controlled.

Walter Ze’ev Laqueur was born in Breslau, the city that is today Wroclaw, Poland, on May 26, 1921. His father made and sold overalls, and his mother was a homemaker.

As a scholar, Mr. Laqueur would devote years to deconstructing Europe’s submission to and recovery from fascism. He edited “The Holocaust Encyclopedia” (2001) and wrote volumes including “Weimar: A Cultural History, 1918-1933” (published in 1974) and “Fascism: Past, Present, Future” (1996).

At times, his books seemed like efforts to understand his own life. In “Generation Exodus” (2000), he wrote about the young Jews who escaped Nazi Germany, and in “The Terrible Secret” (1980), he explored outside knowledge of the Holocaust as it was unfolding. In the latter volume, which documented what he regarded as failures to understand and act among Jewish and non-Jewish leaders around the world, he wrote that “when all allowances have been made, when all mitigating circumstances have been accorded, it is still true that few come out of the story unblemished.”

After fleeing Germany, Mr. Laqueur worked on a kibbutz in the future state of Israel, where, after breaking his leg, he was cared for by a Russian who taught him the Russian language — one of many that he spoke. He later became a journalist in Israel but held no university degree; his youth had been too tumultuous for sustained formal education.

Mr. Laqueur remained intimately connected with Israel long after he left the country to pursue his academic career in Europe and the United States. He was fluent in Hebrew and Arabic and wrote extensively about the Arab-Israeli conflict, including a book-length investigation of the 1967 war, “The Road to Jerusalem” (1968).

Besides his post at the Center for Strategic and International Studies, he served for decades as director of the Wiener Library in London, a renowned center of Holocaust documentation, and taught at Brandeis and Tel Aviv universities.

Mr. Laqueur published two novels about a Holocaust survivor, “The Missing Years” (1980) and “Farewell to Europe” (1981). His memoirs included “Worlds Ago” (1992) and “Best of Times, Worst of Times” (2009). Among his most recent books was “Reflections of a Veteran Pessimist: Contemplating Modern Europe, Russia and Jewish History” (2017).

Mr. Laqueur’s first wife, the former Naomi Koch, died in 1995 after 54 years of marriage. Survivors include his wife of more than two decades, the former Susi Genzen Wichmann of Washington; two daughters from his first marriage, Sylvia Laqueur Graham of London and Shlomit Laqueur of Jerusalem; four grandchildren; and 10 great-grandchildren.

For all the seriousness of his work, Mr. Laqueur looked with humor on his place in the academic pantheon, where, he noted, scholars are frowned upon when they veer too far from a single narrowly defined field or into fiction, as he had dared to do.

“It’s not considered comme il faut,” he told The Washington Post in 1981. “You see, in the academic world, if you publish one book you’re competent. If you publish two, you’re a genius. If you publish three, you’re a charlatan. So that places me . . .

“On the other hand, if you live long enough, you become an elder statesman whether you want it or not.”