During the Cold War, Russian power moved to the East. This allowed foreign countries, like America, to take advantage of the Russian economy. Ukraine left most of its relations with Russia and started its relations with America.
Trusting the U.S.
The U.S. and Europe decided to station themselves in Ukraine around the time of the Cuban missile crisis. ch power wanted to "arm" Ukraine. But, in the end, they decided to take any of their firepower out of Ukraine.
U.S. and Europe in Ukraine
Europe and the U.S. considered accepting Ukraine into NATO. But, after consideration, they didn't. Russia would have responded violently, had Ukraine gone into NATO. There may have been an entirely new war between Russia and Ukraine.
Ukraine and NATO
In 1954, soviet leader Nikita Kruschev transfered the Crimean Peninsula to Ukraine. The Ukranians decided to have an armed resistence against the Russians, which only ended with the capture of the last commander of the Ukranian insurgent army. In 1960, Ukraine opposed Soviet rule even more, which ended up leading to the repression of dissidents in 1972.
Russia using Ukraine
Russia "lost interest" with Ukraine while the U.S. was just becoming friends with Ukraine. Russia was still breaking down from the cold war during this time. But, soon after, Russia will begin their post-cold war period.