JERUSALEM — Sometimes a quitter really does quit for good.

The Palestinian Authority president, Mahmoud Abbas, announced last week that he wouldn’t run for re-election in the proposed January elections. Back when he was Yasser Arafat’s deputy in the Palestine Liberation Organization, Abbas sulked off to his home in the Persian Gulf several times. As Arafat’s prime minister, he quit in the middle of the intifada, accusing the Palestinian leader of undermining him and slamming the U.S. for failing to back him fully.

Each time, he slipped back from exile, until he took over from Arafat on his death and was elected to office, in January 2005. But the 74-year-old now says that he’s exhausted by the political events of this past year, particularly the failure of the Obama administration to pressure Israel on continued settlement-building in the West Bank.

At first, Abbas’s announcement was interpreted as a ploy to press Washington and the Israelis. Israeli, European and Arab leaders called Abbas to beg him to stay on. The West has long banked on Abbas, one of the formulators of the Oslo Peace Accords, as the best hope for a deal with Israel. If he were to go, things might look bleak for peace. (Not that they don’t look bleak right now.)

Despite the phone calls to Ramallah, most leaders assessed Abbas’s move as a tactic rather than a genuine expression of finality — like an actress pouting in her trailer until the director strokes her ego. After all, Abbas said only that he wouldn’t run in the January elections. It’s far from certain that those elections will be held, because Hamas won’t allow a poll in the Gaza Strip, which it controls. That would leave Abbas in office, in spite of his announcement.

Then Palestinian officials started talking to local and international media about what they claimed were Abbas’ true feelings. To sum up: He’s really had it with the Israeli government’s intransigence, and the way the U.S. backed down over settlements was the last straw.

Abbas’ supporters added that if he were to quit, the entire Palestinian Authority might collapse. It is, after all, fairly unloved among Palestinians. The only politician to have told his aides he would run to replace Abbas, Marwan Barghouti, is serving a series of life sentences in an Israeli prison. There are also plenty of Palestinian leaders who hanker for the old days of backroom political deals and lucrative private trade monopolies, which were nixed by Abbas and his Prime Minister, Salaam Fayyad, a U.S.-trained economist.

Still an institution that receives more than $1 billion in international aid each year is unlikely to just go away. For that kind of money, someone will be found to keep it rolling. The threat of collapse seems like an attempt by Abbas’ friends to demonstrate how peeved he is.

So why is Abbas out of patience?

Early in the year, the new U.S. administration pushed Prime Minister Benjamin Netanyahu for a true freeze on building in Israel’s West Bank settlements. Washington insisted the freeze include so-called “natural growth,” which Israel uses to expand its building in the West Bank under the guise of new housing for existing residents.

But Netanyahu didn’t cave. During an Oct. 31 visit to Jerusalem, Secretary of State Hillary Clinton praised Netanyahu for showing “restraint” on settlement building. Restraint, Arab leaders pointed out, is not quite a freeze.

U.S. diplomats seemed to have been slipping toward this climb down for some weeks. Abbas already called Obama late last month to complain about it. That was when he first broached the idea of quitting.

Abbas had, after all, conditioned the resumption of peace talks on a total Israeli settlement freeze. He edged out onto that high diplomatic branch because he thought the U.S. was behind him. Gradually he saw that he was going to be left on that limb.

Backing down on the settlements isn’t an option for Abbas. He’s already seen as weak and vacillating by ordinary Palestinians. Over the summer, he backed off when the U.S. pressed him not to insist on an International Court of Justice trial for Israel, after the release of a U.N. report into the Hamas-Israel war in Gaza at the turn of the year.

Palestinian public outcry forced him to shift his position. But it was too late. He appeared to have confirmed long-standing suspicions that he lacked strength. Perhaps really quitting is the only thing that will show he can make a plan and stick to it.