The movement to put a stop to the War on terror was never going to be effective if waged on U.S. soil. Our effort would have been purely reactive. Overseas we were able to target the heads of the organization and blow the terrorist ideas right out of the heads that thought them up. In an organization that is poorly funded, poorly organize and has no true structure, it becomes impossible to effectively target what should be the heads of the organization. It became an issue of "Nobody really knows who's in charge overall".
The best example I can sum up is the Mexican Mafia. While the original organization has founders, leaders, CEOs, presidents ect...Ect...Ect, the offspring of the MM are all over the U.S. and while influenced by the original organization...They're not truly a part of it. So in essence you could completely destroy the foundation of the MM and still technically have sprouts of it all over the place. It took deployment after deployment after extended deployments to round up and kill every single threatening entity that made itself known in the war on terror...And even then the ones who stood back and bid their time remain at large and they were smart for doing it.
Okay, never mind the fact that no WMD were found once we were in there. Never mind the fact that there are still bombings going on. Keeping the war over there is a whole lot better than having it over here. Yes it did help the War on Terror by bringing freedom to a place that did not have it.
Look at Iraq now and Look at it before the war all the Iraq war did was make things worse. If Saddam was still in power not only would there be no Isis. Iraq would be far more stable and so would the rest of the middle east. There would be no Isis problem in Syria either.
No the war in Iraq did not help the war on terror, it only made them angrier. Yes there has not been another attack on the scale of 9-11,but they have come in drones of small attacks more and more often to fight back against Americans being on their soil.