WASHINGTON — Stephen Hanson, the vice provost for international affairs at the College of William and Mary, summed up what life has been like these past decades for people in his line of work. “I’m a Russia specialist,” he said. “Nobody has been interested in me for 20 years.”

Sure, relations with Moscow could be prickly, and there was that bloody little invasion of Georgia in 2008 that led to Russia recognizing Abkhazia and South Ossetia (close to 20 percent of Georgia’s territory) as independent states, but the consensus was that the Cold War struggle with Moscow was over, replaced by a “reset” relationship that hovered somewhere between cooperation and rivalry but would not lapse again into the outright confrontation of two ideologies.

In this scenario, experts like Hanson were not in heavy demand. Their field had become secondary. Russia was 20th-century news. New members of NATO like Poland or Estonia squawked from time to time about the enduring threat from Vladimir Putin’s Russia, but their anxieties were dismissed as the hangover of decades within the mind-twisting Soviet empire.

Nothing was so certain to put audiences to sleep as talk of “trans-Atlanticism” or the need for increasing European military budgets. As the trauma of 9/11 faded and America’s wars wound down, “pivot to Asia” became the modish geopolitical phrase in Washington. Pivot to Europe was a laughable idea.

None of this was lost on Putin, who actually meant it when he described the breakup of the Soviet Union as the “greatest geopolitical catastrophe” of the 20th century....