So, Senator Chris Coons, what do you think of the Iran deal?

There’s a pause. I have spoken a few times in recent weeks to the Delaware Democratic senator, because a) he is deeply immersed in the details of this negotiation and b) he’s coming from what seems to me roughly the right place here: He wants to support his president and he wants to see diplomacy succeed, but he doesn’t trust Iran and he wants a deal that has a chance of actually working. He’s thoughtful and smart and not a demagogue, and his ultimate support (or not) of the thing really will hang on the details and what he concludes about them.

So he opens by telling me that he first wants to give credit to President Obama and John Kerry for getting this done, because any negotiation is hard, this one almost incomprehensibly so. Then he gives an answer: “It seems on the face of it from press accounts to meet most of the goals that were set.” He hadn’t read it yet, but he’d read enough about it to draw a few conclusions.

Still, Coons says he hasn’t made up his mind yet how he’ll vote. “I’m aware that it’s easier to be critical than supportive because this deal is so complex and the stakes are so high,” he told me. “I do think the diplomacy was worth exploring.” He wouldn’t say this, of course, but it seems to me unlikely that Congress can kill the deal; Obama needs the backing of only 34 senators, which would result in a failure to override his certain veto of a “no” vote. It’s hard to imagine he can’t get that.

We’ll circle back to Coons, but first let’s acknowledge a point that liberal Obama-backers everywhere ought to acknowledge in this case: The deal is a big gamble. Nobody can know today that it will work in the main goal of keeping the Islamic Republic from getting a nuclear weapon. Of course, nobody knows for certain that it will fail either, and Lindsey Graham and Tom Cotton and John Boehner’s instant and predictable Munich-ification of a deal they obviously hadn’t even read was revolting.

But the way to counter their false, know-nothing certitude is not with more false, know-nothing certitude. From a liberal internationalist point of view, it’s clearly a good thing that Obama is trying to shift the reigning Washington foreign-policy paradigm from war-making to deal-making. The war-makers have been wrong about everything for the last 15 years, have told us endless lies, have harmed American credibility, have sown destruction and death—and, by the way, have done a hell of a lot more to strengthen Iran than we doves have. So deal-making is a fine principle for which to strive. But that doesn’t mean the deal is without risks and downsides, and liberals do themselves and the world no favors by not acknowledging them just because Tom Cotton is such a dreary soapbox haranguer.

Here were Coons’s four concerns in the order he listed them to me. First, the inspections regime; second, the timing of the sanctions relief; third, the degree to which the International Atomic Energy Agency will be able to keep track of the possible military dimensions of Iran’s nuclear activities; and fourth, restrictions on centrifuge development after about year 10. “I need to have a much better sense of the breakout time after 10 years,” Coons said, noting concerns that limits on centrifuge development might ease after the tenth year.

For my money, Coons’s second concern is the biggest potential problem here. Iran will get a $150 billion windfall starting in December, and while the regime will presumably spend some of that money at home, it’s a certainty that the Syrian regime and Hezbollah and Hamas and the Houthis in Yemen are all going to get their share.

Combine this money with the deal’s lifting of the conventional arms embargo, which hasn’t gotten much attention yet but you can be sure will get more, especially once Congress starts holding hearings on this, and you have a recipe for Iran to make far more trouble in the region than it has been in recent years. It should not comfort Americans, and American liberals in particular, that the likes of Bashar al-Assad and Hezbollah leader Hassan Nasrallah, both busy murdering Syrian children and suppressing any chance of real democracy being able to grow in Syria and Lebanon, praised the deal to the heavens.

Coons told me he had a lengthy phone call with Joe Biden on Tuesday, and “that’s precisely what I was discussing with the vice president.” He said he’d let Biden speak for himself, but he did tell me that he pressed Biden on questions like what we’d be doing to beef up our commitments to our allies and to check Iranian influence. He says Biden assured him that stern measures were in the works. We’ll see about that. This, too, will be much discussed in the upcoming hearings, and it’s not only Republicans who have these concerns.

Obama says people should judge the deal only on whether it prevents Iran from getting a nuclear weapon, that it isn’t designed to change the nature of the regime or address regional terrorism. What this means is the administration made the decision that keeping a nuke out of Iran’s hands was the job that took precedence over all other tasks. All in all that’s probably the right call. Lindsey Graham said Tuesday that this deal would start an arms race. Not if it holds. If anything, it’s the opposite that’s true: Without a deal, Iran would surely develop a bomb more quickly, leading Saudi Arabia and perhaps others to do the same.

But surely Obama doesn’t mean to suggest that we shouldn’t discuss the other possible consequences of the deal. American liberals in particular should discuss these things. Nuclear nonproliferation is an old-school liberal value, but so is seeing our country take stands against the fundamentalist extremism that Iran exports and the kind of slaughter of civilians we see in Syria.

I was pleased to see that Hillary Clinton’s statement on the deal took both of these concerns seriously. Oddly, it’s not on her website. I got it via email, and the part that impressed me says this: “Going forward, we have to be clear-eyed when it comes to the broader threat Iran represents. Even with a nuclear agreement, Iran poses a real challenge to the United States and our partners and a grave threat to our ally Israel. It continues to destabilize countries from Yemen to Lebanon, while exacerbating the conflict in Syria. It is developing missiles that can strike every country in the Middle East. And it fuels terrorism throughout the region and beyond, including through direct support to Hamas and Hizballah. We have to broadly confront and raise the costs for Iran’s destabilizing activities...”

That’s real liberal internationalism, and I hope she spells out in the coming weeks what “broadly confront” means. I’d rather have her doing it than Jeb Bush or Scott Walker.