For Russian President Vladimir Putin, the ability to deny Russia's involvement in the conflict in eastern Ukraine has always been of utmost importance. The Kremlin has stressed that it is not a party to the fighting, and that all it wants from Ukraine is peace and a few trade concessions. Deniability, however, is fast eroding. Despite increasingly surreal disavowals from Moscow, it is now apparent just how invested Putin is in the conflict's outcome. That investment terrifies Europe and the U.S., which have no desire to match it.