@Mr Shaman,
It's nothing new. We gave the Taliban and Al-Queda weapons when the Soviets attacked Afghanistan, and then we fought the Gulf War, and now this war. It's not even different from history. Some British officers trained Americans during the French and Indian War, and then they fought the American Revolution against the same trained men, and later the War of 1812.
Obviously, the terrorist's enlisted men have changed. However, their leaders have not and we have trained their leaders also.