Then again, it might well be simply a tactic. Take a look at the Israeli response:
"It is not worth the paper it's written on," the Israeli source said about the truce, and calledThe ceasefire, then, might simply be a tactic. A lot of the debate in the conflict between the Israelis and Palestinians has been over culpability- not just over who started it, but which side is "provoking" the other to action. The Israelis say that they must defend themselves against terrorist attacks, whereas the Palestinians say that were they to eschew violence, the Israelis would simply expand the settlements to the point where a Palestinian state is impossible.
on the PA "to take the necessary steps to eradicate terrorism, dismantle the terrorist
infrastructure, collect illegal arms and end anti-Israeli incitement."
For its part, he said, Israel "will take whatever measures are necessary to defend our
citizens when they are attacked." Israel had already said that it would continue
to act against Palestinian "ticking bombs," despite any cease-fire agreement reached
between the PA and militant groups.
(This is, of course, leaving aside the hard-core "get rid of 'em all" factions on either side, although its undeniable that the Palestinian version is more extreme and likely more numerous. Then again, they've also been losing, and extremism often results from military and political defeat. That's a debate I'm not getting into right now, however.)
Since both sides claim that the other is the instigator, the key question is "what would happen if one side stopped?" Hamas and Co. may well be banking on the Israelis to continue their assassinations of top-level terrorists/militants/whatever even in the face of their counterparts' seeming willingness to put their weapons aside for a little while. If Israel does what the Palestinians expect, then the Palestinians can claim that this is evidence that Israel has no interest in a peaceful solution. That probably won't fly in the United States and Israel, who are likely quite aware of the tactics here. It woud, however, boost the status of the Palestinians quite a bit in Europe and in the Muslim world, and gain "Arab street" support that might goad the Arab states into supporting Hamas and Co. more than they were after Iraq's conquest. It also weakens the status of Abbas and the PA, and brightens Hamas' star.
On the other hand, if the Israelis hold off and start following the "roadmap", then it's Hamas and the rest that are put in an intolerable situation, because they're trapped between either moving towards moderation (territory that Abbas and the PA already own) and likely irrelevance, or giving the PA time to rearm itself and crack down on its greatest competitor for power and influence over the Palestinian people. It might also lead to, well, peace, and that also would be a devestating blow to the power of Hamas.
(Unless, of course, they reposition themselves as a peaceful political opposition to the PA, but that can get you killed if you alienate the wrong people without some sort of percieved benefit that outweighs the loss of "radical purity". I don't know if that's actually happening, but I doubt it.)
So it's a gamble, a very deadly one. Hamas is probably confident that Israel will attack them, so they likely think they've got pretty good odds here, but it's still a gamble. Then again, politics- even the violent terroristic kind- usually is.
(Edit: It is also possible that Hamas, IJ, or Al-Aqsa would attack first. That would be extraordinarily foolish, as it would give the Israelis carte blanche to eradiate them and do pretty much whatever they wish in the Territories. Outside observers would be quickly convinced that the "cycle" is the responsibility of the Palestinians, and support for the cause would probably dwindle, especially in Europe. That's also part of the gamble, because one never knows whether a small splinter group might attack even when the big ones are holding off. )