Similarly, Israeli politicians assert that it is not terrorism that has chased Israel from Gaza but the realization that a minority of Jews (about 8,500) cannot manage a majority of Arabs (more than 1 million), and this is surely the case. But it was terrorism that made that point so powerfully. After all, Israel took Gaza from Egypt in the 1967 war. It took 20 years for the Palestinians there to launch their first uprising. Without the violence, Israelis would still be farming in Gaza.

Israel in Gaza, like America in Iraq, underestimated its enemy. Palestinians have been tenacious, not merely fighting but doing so in ways that elude our understanding. Since the 1993 Oslo accords, there have been more than 90 suicide bombings. Israel has responded wisely by erecting a security fence. It has not responded by pulling out of the West Bank. But what's true in Gaza is also true in the West Bank. For Israel, the numbers are all wrong -- too many Palestinians, too few Jews. Ultimately demographics will trump Zionism.

The same holds for Iraq. There, suicide bombings are an almost daily occurrence -- more than 400 since the U.S. invasion in March 2003. The guerrillas, the insurgents, the terrorists -- who are those guys, anyway? -- attack U.S. forces an average of 65 times a day. The insurgency is unrelenting, and so is the mayhem. Sunnis and Shiites are at each other's throats, killing and retaliating and killing some more. No one, it seems, can figure out who is allied with whom. The thing's a morass, a mess, a mystery and, unforgivably, a surprise. This was not supposed to happen. American troops would be greeted as liberators. Remember? There would be no insurgency. Where would it come from? What would be its purpose? Who would possibly die for such a cause?

The smug ignorance is appalling. We understood so little about Iraq. We thought it was just another place where people wanted to be free and vote for the school board. Even today U.S. officials cling to their ethnocentric aspirations. Secretary of State Condoleezza Rice likened the Alabama of her youth -- racist, sometimes violently so -- to Iraq and Afghanistan. "I look at [our history] and I say what seemed impossible on one day now seems inevitable," she recently told Time magazine. "Well, that's the way great historical changes are [made]. And it's why I have enormous conviction that these people are going to make it."

It's a nice sentiment, but it is, above all, sentiment. I don't think Rice is necessarily wrong, only that she has imposed her priorities on a people who have more urgent concerns and historical fears. More than democracy, Iraqis want security. And security is a tribal matter, a sectarian matter -- a matter that cannot be left in the hands of a government led by others. Any country can hold one election. It's the second that matters, the one in which losers become winners -- and the winners respect the rights of the losers. Can Iraq do that? It doesn't look like it.

America and Israel are different. But both are Western democracies, with similar -- not identical -- cultures. It's impossible to conceive of American suicide bombers; it's just as impossible to conceive of Israeli ones. The Islamic world -- the Arab world in particular -- is fighting its own way, rejecting an alien culture the way the body rejects a foreign cell.

Israel left southern Lebanon. Now it's leaving Gaza. America will leave Iraq -- not in success but in failure. These are all discrete events but they are linked by issues of culture and a willingness to use terrorism. Connect the dots. They lead, step by step, to the next exit.