If that headline makes no sense to you, welcome to the world of polling on the Iranian nuclear deal.

That’s great news for Obama. Republicans on the Hill are jumping up and down this week, insisting that the deal all but guarantees an Iranian bomb in the next decade, but voters obviously disagree. Except … no, they don’t, not really:

Only 23% of Americans are even somewhat confident the deal will prevent Iran from developing a nuclear weapon, while 27% are “not so confident” and another third are “not confident at all”.

These numbers are consistent with findings before the agreement was announced that showed Americans in favor of negotiations but also distrustful that Iran would keep up with their end of a bargain.

Indeed they are. That’s what I meant about the world of Iranian nuke-deal polling: Surveys taken earlier this year repeatedly showed Americans cautiously supportive of striking a bargain with Iran yet highly skeptical that Iran would honor that bargain. How do you square that circle?

For starters, realize that maybe one in a hundred people on the street could give you even a general sense of what the actual terms of the deal are. This is chiefly a proxy question, at least for partisans, of how much they trust Obama. Democrats do so they’re pro-deal, Republicans don’t so they’re anti. There’s also an element on both sides, although certainly bigger on the left, that believes any deal is better than nothing at this point because it means there’ll be no war, and that’s the most important accomplishment in all of this. The White House itself shares that view. Stopping an Iranian bomb would be nice, stopping an attack on Iran by Israel and/or the U.S. would be nicer. Look again at the numbers above and you’ll find 28 percent of Republicans, a surprisingly sizable minority, in favor of the agreement. Three months ago, when Reuters polled adults on how they felt about the interim agreement reached in Geneva, 31 percent of Republicans said they backed it. (Only 30 percent at the time said they opposed it, although those numbers have skyrocketed now that the deal is final.) For all the noise made by hawks in opposition, a consistent chunk of the party — likely anti-interventionists and libertarians — has been open all along to making a deal that gets “the military option” off the table. Believing that Iran won’t honor its commitments under the agreement isn’t inconsistent with that. It just means that the hard choice of what to do about their bomb program is something we won’t have to think about for a few years.

Here’s the important result from the poll, though, where the big anti-interventionist victory starts to break down. YouGov asked, “If Iran breaks the terms of the agreement and begins developing a nuclear weapon, would you approve or disapprove of the U.S. and its allies taking military action against Iran?” Behold:

Sixty-four percent overall, including 59 percent of Democrats, would lean towards using military force if Iran breaks its promises and starts building a bomb anyway. What Obama’s done here, whether he and his team realize it or not, is bet the left’s prestige on Iran honoring the terms of this deal. Absent any agreement, the U.S. response to Iran’s decision to “break out” and spin up a bomb core of highly enriched uranium would probably split largely along standard dove/hawk lines. Now that Obama’s staked his legacy on Iran not making a complete schmuck of him, some lefties who lean towards dovishness might think differently if the Iranians cheat anyway. Even beyond the partisan politics of it, the fact that Iran’s made a pledge not to go nuclear for the next 10 years changes the calculus for an American voter who’s otherwise on the fence about whether to use military force. Without an agreement between the two countries, that voter could try to rationalize Iran’s decision to build a bomb: Other countries have nuclear weapons, after all, and Iran might need a big deterrent in a region where it’s encircled by hostile Sunni powers and Israel, and there’s really no immediate security threat to America in an Iranian bomb until they have an ICBM system. With the agreement in place, though, the calculus becomes more of a straightforward matter of broken promises and national prestige. They suckered us into lifting sanctions and obviously they don’t care about international norms if they’re willing to cheat on something as serious as nuclear war, so yeah, maybe the hawks are right that we can’t trust these people to behave like semi-rational actors. Bombs away. The seeds of majority support for a Republican president’s decision to hit Iran may have been planted by this deal.