This war is not big enough today. As demonstrated in Iraq, our enemy cannot withstand direct combat with our army on the scale that was being fought. Without this attrition to sap his strength, our enemies will be able to develop new capability. This must be prevented, at all cost. This is worth waging war over. In other words, invading other countries. I would pick Syria, but politics make ANY aggressive move like this impossible. The problem is the U.S. government is going in quite the opposite direction.
By allowing the war to slow down, we will allow our enemy more time. Time is NOT on our side because sooner or later the war will come to us. Playing good defense is important when you are losing. The withdrawal at Dunkirk saved a sizable portion of the English army AFTER they had been soundly defeated. As a general rule, when you are the stronger, it is to your advantage to press the issue. You can then decide the tempo of the war and the focus of where the fighting is taking place. You decide what targets to attack and force your enemy to defend what he must. This is called the strategic initiative. This can be lost voluntarily or in many cases, by outright defeat.
Seeing as the U.S. has not been defeated outright, any loss of strategic initiative will be voluntary. The war will become quiet. "The calm before the storm." At that point, our enemies will decide where the attacks will be made and we will have to react to their moves. They will be setting the tempo, not us. When these conditions occur, our enemies can be expected to be developing new capabilities. Once again, it will only be a matter of time before we find out what these new capabilities are.