I need to go blog a bit on this as well, but want to leave one thoguht here - this is a proxy war, in which the Arab states - including up to a month or so ago, Iraq - were heavily subsidizing Palestinian terrorism as a tactic. It was ostensibly a good move, relatively cheap, deniable, and cost-free to their own people while maintaining the sense of combat that the totalitian state requires to survive.
Over the next 18 months, for one reason or another, that level of outside cash and logistical support is going to decrease substantially.
Time is on our side, for one.
In many respects, this is fair enough. It's important to remember, however, that support of the Palestinians is also a survival issue in that Palestinian refugees are significant destabilizers in several arab countries (and others where there are interests involved, such as between Syria and Lebanon). There is likely also the perception, justified or not, that a "non-resistant" Palestinian population would be taken advantage of by the Israelis, perhaps leading even to transfer. (Which is a Worst Case Scenario for almost every arab state in the Middle East.)
Anyway, the issue is where this goes. While they may be undemocratic, the leaders of most Arab states aren't stupid or irrational (to the extent that they would ignore situations that benefit them...witness Egypt's peace pact with Israel, and the ruthlessness with which most arab leaders have risen to power.)
If said Arab states get the impression that the Israelis are negotiating in good faith and that the Americans aren't trying to push the process to serve their own ends, then they'll likely do exactly what you said... throttle back on both the rhetoric and the cash supplies for the militant/terrorist groups. (They likely won't abandon either, but it'll go from a torrent to a trickle.)
On the other hand, if the Arab states perceive that Israel is attempting to take advantage of increasing Palestinian quiescence by enacting a slow takeover of "Judea and Samaria" by expanding settlements and claiming large "security zones", then they will start resisting. They'll worry about the prospect of Israel slowly pushing the Palestinian population slowly towards the Jordan river (and, presumably, over it), especially as the "Demographic Dilemma" becomes more and more pressing. Fearing the possibility of the Palestinians irrevocably destabilizing their own states, they'll feel forced to reopen the floodgates, but find a newer and more secure channel by which to do it.
Of course, then the U.S. will have to intervene militarily across the region if it wants to damp this down, and I honestly doubt whether that will work. The U.S. would be forced to occupy and "regime change" multiple countries simultaneously, likely without any sort of U.N. or foreign state support. Indeed, it'd break the two sides of the Atlantic apart for good.
The best solution, then, is for the Israelis and their American backers to entirely give up the rhetoric of assigning blame (not that both sides are necessarily equally blameworthy, but that it's useless and counterproductive), negotiate in good faith, dismantle the settlements, disavow the entire concept of "Greater Israel", (whether it be "Jews on one side of the Jordan, Arabs on the other", the League of Nations' promises, and the use of the term "Judea and Sameria" to describe the West Bank) and work from there.
Does this mean that Hamas and the like won't still scream about Israeli betrayal and the need for jihad to regain all of historical Palestine? Probably not. They might even attack again, which will be counterproductive from a utilitarian perspective, wrong from a moral perspective, and tragic from any perspective. Thing is, people will stop listening to them. Even if they dislike or even loathe the Israelis (although I suspect that opinion will fade away in the light of day), the Palestinians will move to the more peaceful relationship with their neighbours that they had prior to the current intifada, and the extremists will be starved of attention, manpower, resources and public support.
Like the Israelis, the Palestinians have better things to do than fight.