The Obama administration is hearing growing calls to permanently station a substantial number of troops in Eastern Europe as a deterrent to Russian President Vladimir Putin.Putting a large number of U.S. or NATO troops in Eastern Europe would violate a 1997 treaty with Russia, but those arguing for the placement say Putin already broke that treaty by backing the takeover by Russian-backed groups of Ukrainian territory
Source: Obama hears calls to place US troops in Eastern Europe | TheHill