Mitt Romney’s London Olympics blooper got all the headlines, but another gaffe foreshadowed his disastrous comments in Israel — and revealed how unprepared he is to be the most powerful man on the planet.

Romney’s serious tongue trip was blithely mentioning that he’d had a meeting with the head of the MI6, Britain’s intelligence agency.

A real no-no in terms of protocol, but here’s the deeper problem: Should Romney win in November, just how special will our relationship with Britain be when he can’t be trusted to keep his mouth shut about something so simple?

And now, of course, Romney has gone to Jerusalem and talked about “the hand of providence” (i.e. promised land) and how surely culture is a big factor in why Israel’s economy dwarfs that of the Palestinian occupied territories — except that Romney didn’t mention the occupation, that Israel controls all traffic to and from the territories, or that the Palestinians have no currency of their own.

What was he thinking?

PLO officials have called him racist (for good measure, in the same speech, Romney also suggested that culture had something to do with the U.S. beating Mexico economically), have implied that he’s an ignorant fool, and everybody and their more, or less, impoverished neighbor has something to say on the matter.

Big, big news —  but the real damage actually came earlier.

The first and most significant of Romney’s pronouncements in Israel was that he’d support unilateral action by Israel against Iran.

If you’re Iran, how does that play? What in that particular statement would ever make you want to sit down and talk to this man or anyone representing him?

And then, of course, there was calling Jerusalem Israel’s capital and obliterating in a single stroke any Palestinian claim to the city. (Romney also promised to move the U.S. embassy from Tel Aviv to Jerusalem, which no U.S. president since 1950 —  including Nixon and Reagan — had ever suggested.)

Yes, yes — I know with these comments Romney’s really playing to American Jews — especially the very rich ones who travelled with him to Israel — and American evangelicals, not to Jews and Palestinians.

But Jews and Palestinians are listening, as is the whole world. And if Romney wins in November, the Palestinians will have no reason to trust him, and the Israelis will pressure him to keep his summer promises.

If he doesn’t follow through, the whole world will see his cheap pandering for what it is.

And if he does follow through and move the embassy and stand with Israel in any attack against Iran, he will not just betray his weakness but be complicit in what will no doubt be a horrible war.

And even worse: He will embolden ruthless leaders all over the world to follow Israel’s example in dealing with their own perceived threats.

Nice work, Mitt.