The Ukraine crisis and the German-American dispute over American intelligence and National Security Agency practices are without much doubt the beginning of the end of the American-dominated Europe we have known since the collapse of communism. The breakup may be dramatic, or polite and prolonged, but it certainly will come.
I would argue that the European Union is chiefly responsible for what now is happening in Ukraine. The passion for expansion that has overtaken the EU Commission since the 1990s was founded in a reasonable and admirable concern for the political and economic rehabilitation and the future of the former Warsaw Pact states. The decision made was to offer them eventual EU membership.
The United States was, at the same time, a third party to the negotiation of the reunification of Germany, which created what Russia regarded as a troubling revision of the military balance in Europe. Russia was also suffering a series of domestic upheavals, beginning in 1991 with the coup which removed Mikhail Gorbachev from leadership of what was then the Soviet Union and his eventual replacement by Boris Yeltsin, who dissolved the USSR.