Secretary of State John Kerry's ongoing bid for a peace agreement between Israel and the Palestinian Authority might seem a quixotic mission, given decades of failed peace efforts. But paradoxically, the current turmoil in Syria might present both sides with their best opportunity for getting to "yes" in 45 years.

A major obstacle to agreement has been the split between the radical and pragmatic wings of the Palestinian movement. Whenever the pragmatic wing headed by Mahmoud Abbas seemed to be moving toward peace with Israel, the radical elements backed by Iran and Syria, Hezbollah in Lebanon and Hamas in Gaza, would do all they could to wreck the deal. Their obstruction included cross-border attacks on Israel and threats to the moderate Palestinian leadership.

In the six months since President Obama's special envoy Martin Indyk relaunched U.S. efforts to find a path to a peace agreement, the radical elements have again announced their opposition and made efforts to provoke Israel and threaten Abbas. The rising number of attacks has alarmed Israelis, particularly rockets fired from Lebanon and a sniper murder of an Israeli civilian on the Gaza border.

But it is clear that Hezbollah is preoccupied by the civil war in Syria, its main base of support. The civil war appears also to have prevented radicals based in Syria from dragging Hamas-led Gaza more deeply into a conflict with Israel.

Over the past six months Ambassador Indyk has been able to persuade Israel to release a significant number of Palestinian prisoners despite Israeli fears that they will commit acts of terrorism against Israel. And he has been able to persuade Mr. Abbas that he will make more progress toward a peace agreement if he goes along with the current U.S. plan than if he takes his case to the United Nations, which he threatened to do in 2012.

Meanwhile, the U.S. team has shuttled between the two sides, finding points on which they agree and identifying issues that need to be resolved by further direct negotiation.

Mr. Kerry's current objective is to get the two sides to sign off on what the State Department is calling a "framework" document that spells out areas of agreement and identifies specific areas of disagreement needing further negotiation. The U.S. will then offer specific suggestions for resolving the problem areas.

There have been hints that President Obama may agree to free convicted Israeli spy Jonathan Pollard as an inducement to Israeli cooperation in reaching an agreement.

The window of opportunity may be limited, hence Mr. Kerry's urgency in trying to get both sides across the finish line in the next four months.

The repeated efforts to broker Mideast peace have generally met with failure, even when success appeared within grasp. But that's no reason not to make the effort again and again to defuse the powder keg whenever the opportunity presents itself. Diplomacy has limits, but it's a welcome alternative to carnage.