Some events change the world overnight. Others take years to gestate, and even longer to show signs of influence. They often escape our notice entirely.

Something very important just happened in Eurasia, and the U.S.-Russian relationship will be forever changed because of it.

Since 1991, when the Soviet Union formally dissolved, Ukraine, the giant squirrel-shaped country to the east of Russia, has been flirting with a turn to the West. And for two decades, the European Union has been quite welcoming. Ukraine hasn't had it easy. The transition to a market economy was hard. Russia's unhappiness with the independence of its neighbor made itself known in the form of assassination attempts, poisonings, cyber warfare, and even, a few years ago, a shutting off of gas. What does Russia want? Very simple: They don't want Ukraine to join the West.

They don't want the Ukraine to westernize their economy and political system. They don't want their breadbasket to wind up with the Main Enemy's friends in Europe. This is indeed the silent Cold War after the Cold War.

John Schindler, a military historian, put it succinctly on Twitter: "Since 1991, Ukraine's ultimate political destination — East or West — has been contested and up for grabs. It's over. Now we know."

And Ukraine was THIS CLOSE. The parliament was on the verge of agreeing to the reforms insisted on by the EU. A signing ceremony was scheduled for Vilnius next week. President Victor Yanukovich had decreed that the turn west was the logical course for the country to take. And then he changed his mind. Trade deal with Europe was kiboshed.

And he ordered his advisers to re-open talks with Moscow. His public explanation for the volte-face is probably an iceberg tip: He worries about losing Russia as a trading partner. More likely, he worries about turning Russia into an enemy, awakening the sleeping bear. Russia's first retaliatory step would have been to cut off energy supplies once again, which, in the short term, would wreak havoc on Ukraine's already fragile economy. (EU promises to make up for whatever Russia cut off fell on deaf appears, apparently).

What happens now?

Nothing. Russia browbeats the Ukraine into submission. The Eastern Partnership, the EU's name for its outreach to former Soviet states, is effectively dissolved. Ukraine's decision to remain in Russia's orbit will change the center of gravity when the geopolitical and resource wars of the 21st century heat up, as they are certain to do.