Leaders in Moscow, however, tell a different story. For them, Russia is 
the aggrieved party. They claim the United States has failed to uphold a 
promise that NATO would not expand into Eastern Europe, a deal made 
during the 1990 negotiations between the West and the Soviet Union over 
German unification. In this view, Russia is being forced to forestall 
NATO’s eastward march as a matter of self-defense. 

The West has vigorously protested that no such deal was ever struck. 
However, hundreds of memos, meeting minutes and transcripts from U.S. 
archives indicate otherwise. Although what the documents reveal isn’t 
enough to make Putin a saint, it suggests that the diagnosis of Russian 
predation isn’t entirely fair. Europe’s stability may depend just as much 
on the West’s willingness to reassure Russia about NATO’s limits as on 
deterring Moscow’s adventurism.