Eis het ontslag van Jozias van Aartsen

Editor's note: Aaron David Miller is a vice president and distinguished scholar at the Woodrow Wilson International Center for Scholars and was a Middle East negotiator in Democratic and Republican administrations. Follow him on Twitter. The opinions expressed in this commentary are solely those of the author.

(CNN) -- By now it should be painfully obvious that this latest round of the Israeli-Palestinian crisis in Gaza is fundamentally different than its predecessors.

Unlike the two previous rounds in 2008-09 and in 2012, which ended after three weeks and one week, respectively, this round, now in its fourth week, is infinitely more complex. The rapid failure of the cease-fire put in place by Thursday's agreement only emphasizes that fact. Getting to de-escalation, let alone a durable endgame, will be hard. And here are the five reasons why:

1. Hamas, the political/military paradox: One of the reasons the conflict has dragged on for so long is Hamas' anomalous situation. It entered the crisis -- indeed may have helped to trigger it -- because it was weak, financially bankrupt and politically isolated, and thought it could get Israel and the world's attention through violence. This political weakness has now raised the stakes.

Hamas can't stand down without major deliverables that will justify to its supporters and residents of Gaza the death and destruction its rockets have courted. And right now as attacks against Israeli forces attest, the military wing is dominant. Indeed, militarily it has the power to continue the fight. So there's no real urgency to back off without big gains.

Political desperation, combined with military resilience, ensures the conflict will go on. Indeed, Hamas' goal is probably to launch more rockets against Israel the day before the cease-fire is concluded than on the first day the conflict began.

Hamas can't stand down without major deliverables that will justify to its supporters and residents of Gaza the death and destruction its rockets have courted. And right now as attacks against Israeli forces attest, the military wing is dominant. Indeed, militarily it has the power to continue the fight. So there's no real urgency to back off without big gains.

Political desperation, combined with military resilience, ensures the conflict will go on. Indeed, Hamas' goal is probably to launch more rockets against Israel the day before the cease-fire is concluded than on the first day the conflict began.

2. Iron Dome buys space and time: Perhaps the most stunning success of this crisis on the Israeli side has been the Iron Dome missile defense system's capacity to neutralize the threat of Hamas' high trajectory weapons. With only three civilian casualties, economic damage that is relatively limited and not that dramatic a change in the routine of most Israelis (at least those who don't live close to Gaza) the anti-missile defense system has reshaped the basic contours of the conflict.

On one hand, Iron Dome has pre-empted or at least delayed the need for a large-scale ground incursion into Gaza. But on the other it has given Israeli Prime Minister Benjamin Netanyahu, the political elites and the public the latitude to continue to achieve Israel's objectives.

In short, for Israel, too, there's no real urgency to stand down. With the home front secure, the government needs to worry about two things: Israel Defense Forces casualties (so far apparently tolerable at more than 60 even though that's four times the number in both previous confrontations) and international pressure as a result of the horrific Palestinian civilian death toll in Gaza. And both of these could become magnified in the event Israel decides to launch a massive ground incursion into Gaza.

3. No good mediator: In 2008-09, Israel withdrew its forces and unilaterally declared a cease-fire that held more or less; in 2012, the Egyptians brokered one pretty quickly to end that round. This time around you have plenty of would-be mediators, including the United States, the United Nations and Egypt, all of which were involved in the Thursday agreement. But that agreement reflects the reality that none of these mediators had much influence with Hamas' military wing.

Moreover, all of them misjudged the degree to which Hamas on the ground in Gaza was prepared to end the fight.

There is not a single mediator among them that's trusted by both sides. Egypt -- no longer run by the pro-Hamas Mohamed Morsy -- is bent on squeezing the Islamists and is working closely with Israel. And the United States has no ties or influence with Hamas. And we don't even have a situation where one mediator can work on Israel and party X could mediate with Hamas in a kind of diplomatic tag team. Indeed, the flaws of trying to negotiate a cease-fire by committee were all too apparent in the collapse of the Thursday accord.

4. Expectations, the real problem: Unlike the two previous confrontations or even the second intifada where Israel and Hamas squared off, this crisis is driven by expectations on each side that will be hard, if not impossible, to meet.

Even if the two sides wanted to stand down, they have raised the hopes among their respective publics that can only constrain each of them and prove disappointing to Israelis and Palestinians as well.

Netanyahu wants to avoid a massive ground incursion, yet he's identified an endgame -- demilitarization of Hamas -- that would require the forceful disarming of an organization that isn't going to agree to give up its weapons voluntarily. And the Israeli public, which has backed the current strategy of trying to pummel Hamas into submission, expects an outcome that is more decisive than in previous rounds.

Hamas, on the other hand, seems -- in a cosmic roll of the dice -- to be holding out at all costs and somehow banking that if it does so, Israel will be forced to agree to open up Gaza (or will do so willingly), release Hamas prisoners and expand fishing rights and that Egypt will agree to open up the Rafah crossing.

The more death and destruction in Gaza, the more Hamas needs an explanation at the end of the day to justify the sacrifices and the pain of Gaza's 1.8 million residents. And it's not even clear what the objectives of Hamas' military wing really are. The real tragedy is that the odds against any lasting trade-off of demilitarization for economic freedom seem long indeed without some dramatic change in either Israel's or Hamas' calculations or Hamas' total collapse and defeat.

5. Not enough urgency: It's an inconvenient fact, but the reality is that right now, there doesn't seem to be enough urgency, let alone an imperative for Israel or Hamas to back down. Gaza's public doesn't have much say in the matter when it comes to the Hamas military wing's strategy, and the Israeli public, according to opinion polls, seems enthusiastic about keeping up the pressure. Israel's calculations seem to be to neutralize the tunnel threat and pummel Gaza with air and artillery until Hamas agrees to a cease-fire on Israel's terms.

Hamas wants to survive with its military and political leadership intact, and it hopes that massive Palestinian casualties will galvanize the international community to press Israel to stop and that more IDF deaths will cause Israel to sour on the operation.

So where is this headed? In both previous confrontations, we might have confidently predicted some diplomatic endgame. Not now. For the moment, the focus has shifted from a brief foray into diplomacy back to escalating conflict. The prospects of some kind of an expanded Israeli operation into Gaza are highly likely, with all the casualties that could entail.

What separates this round of the Israel-Hamas battle from the others is that there's no predictable path away from much more bloodshed. And that -- given the tragic loss of life -- is the terrifying truth.

Note: This article was updated to delete references to the capture of an IDF soldier; Israeli authorities now say the soldier was among those killed by a suicide bomber.