Last week, Ukrainian President Viktor Yushchenko issued new restrictions on Russia's use of the Sevastopol port facilities, which included "a requirement that the Black Sea fleet seek the permission of Ukraine's armed forces at least 72 hours prior to ships or aircraft crossing the Ukrainian border. . . " and if "Russia does not fulfill the new requirements, Ukraine may demand that naval ships and aircraft of the Black Sea fleet leave Ukraine's territory immediately."
Since Poland's acceptance of the THAAD (Terminal High Altitude Area Defense) anti-ballistic missile (ABM) launchers and Russia's threat to make Poland a nuclear target, Ukraine reacted:
To the Russians, the Soviet-built satellite facility must be seen as a Russian built facility, which in some fashion must add insult to injury.
Ukraine, no doubt, recognized the reality that it faces the high-probability of being "added to Moscow's nuclear hitlist," but wanted to strengthen its Western ties. Ukraine was also tied to the USSR as Georgia was, and facing the same possible fate as Georgia, Ukraine seems to want to act now instead of reacting to a military intrusion later.