Is Ehud Olmert’s “convergence plan” dead? This may not seem the most pressing thing to ask while the fighting in Lebanon is going on, but since the fighting has a great deal to do with this plan, the question is not irrelevant.

It is doubtful indeed whether, were the Olmert government not so committed to the idea of a unilateral withdrawal from most of the West Bank to borders determined by Israel, it would have reacted to Hezbollah’s abduction of two Israeli soldiers with the fury that it did. Since the withdrawal of Israeli troops from southern Lebanon in 2000, Israel has responded to numerous Hezbollah provocations and threats far more mildly than it did now, and the feeling that “this time they’ve gone too far,” although certainly part of it, cannot by itself explain the launching of such a major operation.

But “convergence” is in deep trouble, and was so long before the fighting in Lebanon began. The unceasing Kassam rocket attacks from Hamas-controlled Gaza had already done the job. What was the point of Ariel Sharon’s unilateral withdrawal from the Gaza Strip, the Israeli public was increasingly asking in the months after Mr. Olmert’s election last March, if it was followed, not by peace and quiet, but by daily shelling? And if this was what happened when the army left Gaza — which is not, given the range of the weapons the Palestinians possess, currently within striking distance of major Israeli cities and strategic installations — what would happen if it pulled out of the West Bank, from which Kassams, let alone longer-ranged missiles, could easily hit Jerusalem, Tel Aviv, Ben-Gurion Airport, and major army bases?

Israeli public opinion has, in recent months, turned more and more against “convergence.” Whereas a narrow majority of the country’s population might have supported it at the time of Mr. Olmert’s election victory, a clear majority today opposes it. And yet as practically the sole campaign plank on which he and his Kadima Party ran, and as the linchpin to his strategic vision of Israel’s future, it is not a plan that he can give up without losing the raison-d’etre of his prime ministership.

The Hezbollah border raid that triggered the fighting in Lebanon needs to be seen against this background. On the one hand, it added yet another argument to the anti-“convergence” camp’s arsenal: Here was yet one more reminder of what Israel can expect when it withdraws unilaterally from territory in which hostile forces are allowed to remain, as Hezbollah was allowed to remain in southern Lebanon in 2000.

On the other hand, it also presented the Olmert government with an opportunity to show both Israelis and the world what Israel’s enemies can expect if they attack it from an evacuated West Bank. What we are doing to Hezbollah, the message went, we will also do to West Bank Palestinians who attack us across the border we establish.

In a very real sense, therefore, the future of “convergence” depends on the outcome of the fighting in Lebanon. If Israel manages to crush Hezbollah, or to pave the way for a political settlement as a part of which Hezbollah will be disarmed and forced to abandon its military positions along Israel’s northern border, unilateral West Bank withdrawal may still seem a viable option. If the results are less than that — if, say, Hezbollah emerges from the weeks of combat and its negotiated aftermath with its fighting units still intact — “convergence” can be kissed goodbye, at least for the foreseeable future.

The Olmert government is thus now fighting in Lebanon for its own political future. If its war aims are not met, Mr. Olmert will in effect be a lame-duck prime minister with nearly four years of office still ahead of him. This to a great extent explains his determination to “go for broke” in Lebanon and order all-out military action.

One wishes him well, not only because crushing Hezbollah is a worthy aim in its own right, and an important part of the war against Islamic terror and the Iranian-Syrian-jihadist axis, but also because “convergence,” for all its problematic aspects, remains the only game in town. Those who criticize it and point to the southern Lebanon and Gaza withdrawals as dire precedents have a serious argument to make. What they do not have, however, is a serious alternative.

The fact is that the Kassam rocket attacks from Gaza, and the thousands of Katyusha and Ra’ad missiles that Hezbollah has fired into Israel in the past two weeks, have certainly strengthened the case against “convergence,” but they have not weakened the case for it. “Convergence” remains one of three possible ways in which Israel can deal with its Palestinians problem — and the other two continue to be far worse. They are: Either continuing the Israeli occupation of the entire West Bank forever, or else capitulating to the Palestinians’ terms for a peace settlement, which would mean withdrawing all the way to the 1967 borders and admitting into Israel large numbers of 1948 Palestinian refugees and their descendants — and that, too, without the slightest guarantee that the peace agreed on would be durable.

If Hezbollah cannot be dismantled as a terrorist threat, and if this cannot serve as a precedent either for doing the same to Hamas or for intimidating it into better behavior, “convergence” can be forgotten about. But Israel will then be in a worse situation than ever, without a ray of hope for extricating itself from an endless conflict. That’s another reason to pray for its success in Lebanon.

Mr. Halkin is a contributing editor of The New York Sun.