The US regards the entire North and South American continents as its sphere of influence, yet asserts the right to park itself and its allies on Russia’s doorstep. From Robert W. Merry at theamericanconservative.com:
Whether in Ukraine or Georgia, Vladimir Putin’s actions shouldn’t come as a surprise to an aggressive United States.
Suppose China formed a provocative alliance with Mexico and began building military bases and stationing troops near the U.S. southern border. Now suppose it lured Cuba also into its new hemispheric alliance and imperiled U.S. control over its Guantanamo naval base on that island. What would happen? Almost inevitably, the result would be war because America would never allow such a potentially hostile entrenchment within its sphere of influence.
That’s essentially the question Russia faces as America and NATO continue to flirt with the notion of pulling Ukraine into the Atlantic alliance (and Georgia too when circumstances seem right). And Russia’s answer is essentially the same: It will not allow that to happen. Any nation has a fundamental need to fend off potential threats from within its neighborhood and hence to maintain protective spheres of influence. The University of Chicago’s John J. Mearsheimer calls this “Geopolitics 101.”