Former Defense Secretary Robert Gates says Russian President Vladimir Putin wants to recreate a Soviet-style sphere of Russian influence in Eastern Europe — an ambition the United States and its allies must keep in check.

Gates told “Fox News Sunday” that Russia’s current military occupation of Ukraine‘s Crimea region is an example of Putin’s long-term strategy for Russia to have “economic, political and security relationships with these countries that make them all lean toward or do the bidding of Moscow.”