The United States and Europe have been trying since 1991 to " detach" Ukraine from Russia. This " democracy promotion" has seen the USA spend upwards of $5 billion, since 1991, "to convert" Ukraine into a Western asset, boasted Victoria Nuland, the asst. secretary of state for European and Eurasian affairs, in Dec. 2013 ( David Bromwich in June 2015 Harpers " What went wrong.... Assessing Obama's legacy). The plan also called for the defamation of Vladimir Putin, which went into full play at the Sochi Olympics and which has continued unabated, to this day. Nuland also showed up in Kiev to hand out cookies to anti-Russian protesters, after the Feb. 2014 coup that overthrew the Yanukovych government. Bromwich also reported on an intercepted phone call between Nuland and Geoffrey Pyatt, the US ambassador to Ukraine, picking the people who they would install in after the coup. This eventually led to the bloody civil war presently raging in Ukraine and undermined American diplomacy with Russia.
Putin's response was to send even more help to the rebels in Ukraine. He was not content to annex Crimea ( which a drunken Khruschev had handed over to Ukraine in the mid-50s), which has always been seen as part of Russia and where the Black Sea fleet was headquartered. Now all of East Ukraine, which is strongly pro-Russian, is in play.
Putin has also developed closer relationship with China and with the former Soviet Asian republics and has caused the Baltic states much concern. He has also accused the government of Ukraine of being run by Nazi fanatics ( many in Ukraine had supported the Nazis during WW2 and some of them have been shown carrying Nazi-like flags at anti-Russian rallies), and is trying to lure EU members like Greece, Cyprus and Hungary to the Russian fold. He has also announced that Russia will place nuclear-capable missiles in the Russian Baltic outpost of Kaliningrad and threatened to move nuclear weapons into Crimea. Thousands of Russian troops have been moved to the Ukrainian border. There have also been probing fly-bys, by Russian jets and bombers and huge land exercises, that have NATO countries very worried.
Putin will not back down. His approval rating is in the high 80s. Obama is nearing the end of his tenure and Europe is leaderless and with Cameron of Britain holding an "in-out" referendum on European membership and bargaining for a new deal, Putin has a strong hand and he will use it.
The 1991 plan to wean Ukraine away from Russia has backfired. The civil war rolls along. Crimea is lost forever and soon East Ukraine will be gone and while the sanctions have hurt Russia economically, Putin continues to plot from the Baltic to the Black Sea, building a new Russian " empire".