Pentagon says WAR on ISIL can last 10-20 Years. Is that a REALISTIC Timetable and why would it take so long?

I think that's an underestimation. If not waging total war (such as WWII), then to change the culture of people who are sworn enemies would take more than a generation.

We will always be vulnerable to homegrown extremists... I don't think it likely that Islamic extremists will disappear 10-20 years, however it is possible that the worst of the worst are calling themselves something else by that time. That said, I don't believe we have any business going to war with ISIL. They are a problem that should be dealt with my Saudi Arabia, Jordan, Iraq, Iran, Syria, Lebanon and Turkey. Not the United States.

SPC Andrew Griffin I believe that I will still be around in 20 years, maybe even 30 years and I can tell you will be reading about another terrorist attack 30 years from now. This enemy we have been fighting now for most the better part of 20 or 30 years now has generations of haters that will keep coming and keep coming until we can truly find a way of changing their hatred for Infidels. I just don't see it happening in the next 30 years unless someone really get serious or we are attacked in such a horrific manner it wakes up the sleeping giant again.

We are fighting an ideal, a radicalized version of the Islamic religion whether people want to believe that or not. Winning this type of “War” will not be fast, cheap, or easy. As the fighting rolls on and casualties build up, and tangible goals or objectives are won then public support will diminish significantly. As public support falters so will congressional support. The style of fighting we are currently vested in is a losing battle in my opinion. We need more support from most of the other Islamic nations and Islamic people in order to realistically “defeat” this enemy. As we continue to encore collateral damage in innocent lives, we cannot win the support needed from the Islamic people in the region or around the world. I personally feel that the more ISIS/ISIL continue to murder not only men, but women and children as well for not adhering or believing in their version of Islam, the more damage they are doing to their own campaign. If the U.S. can reduce collateral damage while allowing ISIS/ISIL to make the mistakes they are making, then conflict will be much easier to win. Ultimately this is a war of public support through propaganda through which ISIS/ISIL, at first, had been dominating. However for them their greed and blatant disregard for the lives of all Islamic people is starting to lose them the support they once had.

If it's a war and not patty cake politics then remember we defeated the 4th largest military in the world in 3 months....If we play at war then yes, decades..... Give the military the mission, pull back the politicians and the press....

I think it's an optimistic timeline at best.

I don't even think this is the type of "war" you can put an estimate on. Vietnam, Operation Enduring Freedom..these were more conventional wars and look at those timetables. I believe we are looking at a completely new breed of war here, and it is one of the types of war that may be here to stay. The timetable may not be estimated with a beginning and an end. It will be like managing herpes.....you can manage the outbreaks, but the disease is always lurking beneath the surface.

It's a real time table because IMO they have no real plan to defeat them.

I think one big issue that is often overlooked is that many people flocking to their cause is the hopeless economic situation they feel they are in, whether ir be in the ME or even in Europe where many folks are traveling from. Kind of what's happening in Palestine, happened in the former Yugoslavia (Serbs) any many other places.

Defeating Daesh will take a very concerted effort over a long period of time if we keep on the current path.