And here I thought Crimea was Putin's revenge for a 15-year slight:

http://www.businessinsider.com/crimea-is-putins-revenge-for-a-15-year-old-slight-2014-3

After the collapse of the Soviet Union, ultranationalist ideologies were decidedly out of vogue. Rather, most Russians looked forward to Russia’s democratization and reintegration with the world. Still, a few hard-core patriotic elements remained that opposed de-Sovietization and believed -- as Putin does today -- that the collapse of the Soviet Union was the greatest geopolitical catastrophe of the century. Among them was the ideologist Alexander Dugin, who was a regular contributor to the ultranationalist analytic center and newspaper Den’ (later known as Zavtra). His earliest claim to fame was a 1991 pamphlet, “The War of the Continents,” in which he described an ongoing geopolitical struggle between the two types of global powers: land powers, or “Eternal Rome,” which are based on the principles of statehood, communality, idealism, and the superiority of the common good, and civilizations of the sea, or “Eternal Carthage,” which are based on individualism, trade, and materialism. In Dugin’s understanding, “Eternal Carthage,” was historically embodied by Athenian democracy and the Dutch and British Empires. Now, it is represented by the United States. “Eternal Rome” is embodied by Russia. For Dugin, the conflict between the two will last until one is destroyed completely -- no type of political regime and no amount of trade can stop that. In order for the “good” (Russia) to eventually defeat the “bad” (United States), he wrote, a conservative revolution must take place.

It WAS Putin's revenge to show the U.S. that we do not set policy for the world, especially not in Asia.