As everybody probably knows, USA started a War on Terror(ism) a few years ago. The mission has certain lack of clear goal, or perhaps, if taken literally, it has a clear albeit an oxymoronic goal.
Terrorism is a form of warfare - it is a method that a group may use to further their political goal. Fighting a war on terrorism is akin to fighting fighting a war to end civil wars, or to end conventional wars between states. We are not going to see end to war in foreseeable future and we are not going to see end to terrorism as a method of warfare. There is no method with which one can eradicate a strategy from the 'manuals' of war.
Fighting a war against particular terrorist organizations, such as al Qaeda, is another matter altogether. A terrorist organization good at what it does is an elusive foe and difficult to fight, but at least fighting against it is at least possible. It is also possible to win such a war, though results are probably never conclusive in the same sense as the victory over Germany was. After all, there is no entity that can surrender and no entity that can announce end to war on the other side. Instead, if victorious the terrorist network in question will wither away losing significance and capabilities to strike.
Unfortunately, there seems to be a misconception between these two things at the highest levels of USA administration which does not bode well for the future.