The conflict in the Middle East may have subsided, but the war is far from over.

NOW that the guns have mainly fallen silent, at least temporarily, a look back can help us look forward. The critical fact for understanding the war in Lebanon and how Hezbollah has enduringly changed the geopolitics of the Middle East conflict is to be found near the beginning.

It is not that Hezbollah seized two Israeli soldiers on July 12 but what it did immediately afterwards. When Israel began responding to the kidnapping - together with the Katyushas striking northern Israel - as the act of war that it was, Hezbollah, in choosing not to return two soldiers, showed that it preferred that Lebanon suffer progressive large-scale destruction.

For the second time in the long history of the Middle East conflict, an enemy of Israel has effectively said: "We do not care what you do. We do not care if our war-making leads you to attack our cities, ruin our economy and kill our people. What matters most is inflicting damage on you, weakening your morale and goading you to destroy more of our country and kill our children, increasing your international condemnation." The Palestinians said as much with their second intifada and their suicide bombing. But this conflict was different because Hezbollah's daily rainfall of rockets in Israel portended an intolerable military assault without end.

What could Israel - what could any country - do with such an enemy? Except for desperate Saddam Hussein during the Gulf War, other countries and armies that would have liked to destroy Israel did not dare target Israeli cities because they knew Israel would more intensely bomb Cairo, Amman or Damascus. Israel had deterrence, its nuclear deterrence inducing Egypt to make peace. Even if an enemy had dared such an attack, Israel could have compelled it to stop by inflicting damage until it desisted. With Hezbollah - and to a great extent with Hamas as well - Israel lost the first two strategic options for dealing with a belligerent, dangerous foe: deterrence and compellence (short of inflicting widespread destruction).

The third strategic means for responding to an enemy, making a genuine peace, has never been possible because Hezbollah and Hamas, by religious or ideological conviction, as they themselves say, are committed to Israel's utter destruction and see any cessation of hostilities as an interlude before further attack. Hezbollah, which built its prodigious missile-terror capacity and perpetrated its acts of war six years after Israel vacated Lebanon, saw the assault as the initiation of its ambition's fulfilment. Its leader Hassan Nasrallah declared: "It is the beginning of the end of this entity."

So Israel adopted the fourth strategic possibility: to devastate its dangerous foe, which it hoped would also restore deterrence. Yet Israel discovered that, against a terror foe whose combatants looked like civilians and whose rockets that reach Israel from afar were hidden everywhere, it must fight longer and occupy and destroy much more of Lebanon than it deemed moral, wise or feasible. Hence its foot-dragging for weeks. Even after an Israeli occupation of southern Lebanon, Hezbollah would continue to fight with no end in sight, including by launching rockets into Israel.

What strategic possibilities remained? The fifth was intolerable: living with ongoing, and probably increasing, rocket attacks into northern Israel and likely the heart of Israel. Nasrallah has promised: "There are many cities in the centre of Israel which will be targeted in the phase of 'beyond Haifa'," which can come sooner or, after an interlude, later.

The sixth option was to re-establish deterrence by striking Hezbollah's suppliers and patrons, Syria and Iran. Neither country wishes a war with militarily superior Israel (Syria's sabre-rattling notwithstanding). If Hezbollah's missiles into Israel produced Israeli retaliation against Syria, and possibly Iran (including its nuclear production sites), then Syria and Iran would be compelled to force Hezbollah to stop. Obviously, this was a last-ditch strategic option that was unattractive and carried its own risks. It would escalate the conflict enormously, as well as the international pressure on Israel to desist. This option, however, had the virtue of being the likeliest to re-establish the deterrence critical to Israel's long-term survival and, perhaps counterintuitively, stability in the region, by demonstrating Israel's enduring power of compellence. And it might have prevented the otherwise certain widespread devastation of Lebanon.

All of Israel's strategic choices were bad or ineffective or undesirable. And now a putative deus ex machina UN resolution has arrived in the form of an international force south of the Litani River, with a mandate to displace but not immediately disarm the rocket-laden Hezbollah. Although this becomes a new, seventh strategic option, of interjecting a new strategic player that could potentially stabilise the region and create a new security paradigm that would allow for progress towards regional peace, it may still prove an ominous defeat for Israel.

Even if the international force seriously tries to do its job of keeping Hezbollah out of this southernmost part of Lebanon, northern Israel will remain in Hezbollah's rocket range (which will only increase with time). Hezbollah can start a guerilla war against the international force, which may not have the wherewithal and staying power to prevail. And it allows an armed Hezbollah with its umbilical cord with Syria and Iran to live on, rearm and fight another day, and to remain, for the Arab world, a proud symbol of its triumph in terrorising and emptying one-third of Israel of its Jews.

Make no mistake; Israel has been fighting for its life. Unexpectedly. Because it faces a historically new kind of fanatical foe, political Islam, which combines three characteristics: a political-religious ideology calling for the annihilation of its enemies; indifference, even the celebration of its own people's death (because such martyrs are rewarded with a place in heaven); and virtually unstoppable technology (missiles) and techniques (suicide bombing) of terror. The spectre of unending terror and unending war haunts and threatens to cripple Israel.

The political Islamists have been emboldened by this new-found power. Nasrallah's boast, whatever his present setback, is resounding through the Arab world: "When were two million Israelis forced to become displaced or to stay in bomb shelters for more than 18 days?"

The political Islamist danger will escalate a thousandfold if Iran, the epicentre of political Islam and Hezbollah's master, achieves its own invulnerability with nuclear weapons so that it, too, can wage its own rocket and other attacks against its many targets, starting with Israel, which Iran's President Mahmoud Ahmadinejad has just reiterated must be annihilated and about which its former president and powerbroker Hashemi Rafsanjani spoke candidly in 2001.

"The use of even one nuclear bomb inside Israel will destroy everything," Rafsanjani said, whereas it would merely harm the Islamic world. "It is not irrational to contemplate such an eventuality."

Whatever the battlefield results, this conflict's enduring effect will be Israel's extreme vulnerability: with simple and cheap rockets, and terrorists aspiring to martyrdom, its enemies can paralyse virtually all of the geographically tiny country. Downtown Tel Aviv is a mere 20km from the West Bank. Israel's political Islamic enemies understand and rejoice over the new geostrategic situation.

The destruction of Israel, which apparently seemed a remote goal worth the long struggle, appears to them to be within their grasp. And the prospect that they would settle for a final peace with Israel correspondingly recedes.

These totalitarians' ultimate targets - all infidels, especially in the US and in Europe - should study the new geostrategic situation as well, be sobered and realise that Israel, in fighting this war in self-defence to re-establish a geostrategic balance and for its long-term survival, has been ultimately fighting for them as well.

Daniel Jonah Goldhagen, an affiliate of Harvard's Centre for European Studies and the author of Hitler's Willing Executioners: Ordinary Germans and the Holocaust, is completing a book on genocide in our time.