NOW that President Obama has finally succeeded in bringing the Israelis and the Palestinians back to the negotiating table, the commentariat is already dismissing his chances of reaching a peace agreement. But there are four factors that distinguish the direct talks that will get under way on Sept. 2 in Washington from previous attempts — factors that offer some reason for optimism.

First, violence is down considerably in the region. Throughout the 1990s, Israel was plagued by terrorist attacks, which undermined its leaders’ ability to justify tangible concessions. Israelis came to believe that the Palestinian leader Yasir Arafat was playing a double game, professing peace in the negotiations while allowing terrorists to operate in territory he was supposed to control.

Today, the Palestinian Authority is policing its West Bank territory to prevent violent attacks on Israelis and to prove its reliability as a negotiating partner. Hamas — mainly out of fear of an Israeli intervention that might remove it from power — is doing the same in Gaza.

These efforts, combined with more effective Israeli security measures, have meant that the number of Israeli civilians killed in terrorist attacks has dropped from an intifada high of 452 in 2002 to 6 last year and only 2 so far this year.

Second, settlement activity has slowed significantly. As a result of Israel’s 10-month settlement moratorium, no new housing starts in the West Bank were reported by the Israeli Central Bureau of Statistics in the first quarter of this year. What’s more, there have been hardly any new housing projects in East Jerusalem since the brouhaha in March, when Vice President Joe Biden, during a visit to Israel, condemned the announcement of 1,600 additional residential units. The demolition of Palestinian houses there is also down compared with recent years.

The settlement moratorium, however, is due to expire on Sept. 26. The Israeli prime minister, Benjamin Netanyahu, seems unlikely to extend it, and Mahmoud Abbas, the Palestinian Authority president, has declared that he will withdraw from negotiations if settlement activity resumes.

However, there could be a workable compromise if Mr. Netanyahu restricts building to modest growth in the settlement blocs that will most likely be absorbed into Israel in the final agreement, while offering changes that would make a real difference to West Bank Palestinians. Israel could promise that there would be no more Israeli Army incursions into areas under Palestinian control; it could also allow the Palestinian police to patrol in most West Bank villages.

Third, the public on both sides supports a two-state solution. So do a majority of Arabs. The simple truth is that most people in the Middle East are exhausted by this conflict, and if Mr. Netanyahu and Mr. Abbas can reach a viable agreement, the public on all sides will likely support it by a large majority.

Yes, Mr. Netanyahu would face strident opposition from within his Likud party, but he could lean on the support of the Israeli center and left to ensure a Knesset majority. And because a referendum on Palestinian statehood would likely receive overwhelming support in Gaza as well as the West Bank, Hamas — always attuned to Palestinian public opinion — would have a hard time standing in the way.

Fourth, there isn’t a lot to negotiate. In the 17 years since the Oslo accords were signed, detailed final status negotiations have dealt exhaustively with all the critical issues. If an independent Palestinian state is to be established, the zone of agreement is clear and the necessary trade-offs are already known.

Security arrangements were all but settled in 2000 at Camp David before the talks collapsed. The increased threat of rocket attacks since then, among other developments, require the two sides to agree on stricter border controls and a robust third-party force in the Jordan Valley. But one year is ample time to resolve this. In fact, if the leaders are sincere in their intent to make a deal, dragging out the negotiations would only weaken them politically and give time for the opponents of peace to rally.

In short, the negotiating environment is better suited to peacemaking today than it has been at any point in the last decade. The prospects for peace depend now on the willpower of the leaders.

Does President Abbas, already a weakened figure, have the courage to defend the necessary concessions to his people, particularly when it comes to conceding the “right of return” to Israel? Does Prime Minister Netanyahu have the determination to withdraw from at least 95 percent of the West Bank and to accept a Palestinian capital in Arab East Jerusalem? And does President Obama have the statesmanship to persuade both parties to make the deal and to reassure them that the United States will be there with a safety net if it fails?

At the end of the Clinton administration, Shimon Peres observed that “history is like a horse that gallops past your window and the true test of statesmanship is to jump from that window onto the horse.” Arafat failed that test, leaving Palestinians and Israelis mired in conflict. We cannot know whether Mr. Abbas and Mr. Netanyahu will take the politically perilous leap. But for the time being, we should suspend disbelief and welcome the fact that American diplomacy has ensured they will soon be put to the test.