The West is a sort of abstract version of “Europe”, which in turn is a secularized version of [Christendom]. As such it is not completely clear what it is or was, except that it wasn’t the “East” (thecommunist world) or the “South” (the Third World). It included New Zealand but not Argentina, for example, and didn’t exclude Japan. See David Gress’s From Plato to Nato for an account of the development of the idea and of the thing itself.
During the Cold War period many conservative and neoconservative publicists pushed “The West” or “Western Civilization” as the main object of conservative loyalty. The impulse has died down somewhat with the collapse of the Soviet Union, the extension of NATO and the EU, continuing mass third-world immigration, the general triumph of multiculturalism, and increasing friction between Europe and the United States.
The conception nonetheless retains some persuasiveness: see Samuel Huntington’s The Clash of Civilizations and the Remaking of World Order, in which he views the West as one of the main protagonists in the future world order. Still, it’s not clear how much staying power it can have given the progressive loss of its principles of identity, cohesion and authority. The basic conflict seems to be that the West insists on universality but like other things can exist only as a particular. Hence its simultaneous will to universal dominion and self-destruction. The conception of God-made-man once reconciled matters, but the post-Christian West is left only with the conflict.