From an article in the February issue of Foreign Affairs:

Never before in American history was there a period quite like it. For 48 days the United States moved inexorably toward war, acting on authority granted by an international organization. ...

George Bush did not blunder into war. At each juncture over a six-month period he weighed his options and made his choices. The president had to maintain an unprecedented and fragile international coalition, retain domestic support for a course that might end in war and bring increasing pressure to bear against an opponent whose very rationality was open to question. The president and his advisers were haunted by lessons learned from the 1930s; they feared Munich more than Vietnam. At the very end the president voiced the same argument that had been implicit since the outset; that the best chance for peace was to threaten war. As of 11:59 p.m. Eastern Standard Time on Jan. 15, that strategy had failed. The next day the war against Iraq began.

Perhaps historians will not remember 1990 only as the year of the Gulf crisis. For Germans it was the year of unification. For the British it was the end of more than a decade of Thatcherism. In South Africa Nelson Mandela was released. In Poland Lech Walesa was elected president. Democratic governments began to take hold in Eastern Europe, while in the Soviet Union there was an ominous intensification of crisis.

Nineteen-ninety was indeed a "defining moment," but the shape of the post-Cold War order was far more uncertain at the end of the year than it had seemed at the begining.