Wars are far less of a problem than they have been at any time in human history. Let us be grateful for that.
Much of what war is left for America to fight has to do with Energy and Terrorism.
We are making war against the Taliban so we can control Afghanistan. We want to control it so we can get Bin Laden. He's a Religious Extremist. He's also a Saudi. And guess what, they are Religious Extremists, too. They like to donate to “martyrs in the cause,” like... Bin Laden. The money they donate comes from oil. So... cut the supply lines, cripple the enemy.
We will always need to defend ourselves. But we can change our current situation by fixing Energy and Terrorism.
Any politician who tells you we need to fight a full-scale war is probably just incompetent, one who fear mongers as the only way to hide his uselessness. Either that or he's an Oil Dealer, a Fuel Kingpin who wants you to join his Gang of Thugs.