Joshua Shifrinson, Foreign Affairs (USA)
During negotiations over German reunification in 1990, did the United States promise the Soviet Union that NATO would not expand into eastern Europe? The answer remains subject to heated debate. Today, Moscow defends its invasion of Ukraine by claiming that NATO reneged on a promise to stay out of Russia’s backyard. Skeptics, meanwhile, counter that Russian claims are a pretext for aggression; in their view, Washington and its allies never formally committed to forego NATO expansion.