Buchanan is right on this --- we're not the same people who defeated Nazism in Europe --- we weren't so politically correct that we made it too complicated. We keep wanting to invite the new Nazis to the White House so they will pray for the conversion of the USA to Islam while we try to figure out which ones are evil to fight.
Iraq is going to show us that nation building isn't very easy because we don't really have what it takes to build nations.
Nazism was defeated by the Soviets (and by the Russians who were the main nation within the Soviet Union). Americans protected Western Europe from Soviet rule.
It's a goofy Wilsonian vision. We're going to give every nation in the world a gift they don't want and haven't asked for and haven't sacrificed for, and we expect them to appreciate it and thank us? Would the US have existed the way it did if France had beaten England on our behalf?