Earlier this year, California Representative Adam Schiff, the ranking Democrat on the House Intelligence Committee, told me he had serious doubts about Iran’s intentions as it pursued a nuclear deal with the United States and five other world powers. He also said he was somewhat worried about the scale of possible American concessions during the talks. Schiff, who I described in a post at the time as a “moderate’s moderate,” suggested to me that he wanted to see President Obama achieve an important foreign-policy success, but as a Jew, he wanted to make sure that an anti-Semitic regime—both he and Obama agree that Iran is ruled by an anti-Semite—would not be allowed to become a nuclear-weapons state. At the time, he told me he was “uncommitted” and that he would “remain uncommitted” until he had time to review a final deal, should a final deal materialize.

Well, the final deal has materialized, and Schiff, in a telephone call over the weekend, told me that, based on an “extensive review,” he has decided to come out in favor of the deal. He said he plans to formally announce his support later on Monday, but that he has already informed the White House of his intentions. His decision should carry some weight with national security-minded Democrats, and with still-undecided members of the House Jewish caucus.

In our conversation, Schiff told me wants to see Obama and Congress work together to strengthen key aspects of the deal—most notably, he wants the administration to promise Iran that the United States will have zero tolerance for any instances of Iranian cheating. But he said he believes the deal could serve its stated purpose: to keep Iran south of the nuclear threshold.

“At the end of the day, I could not find an alternative that would turn out in a better way than the deal,” he said. “Rejection of the deal would not lead to something credible. And I think that there are enough ways to mitigate the risks associated with the deal that it makes sense to me to move forward.” He went on, “The risks associated with rejection of the deal are quite a bit higher than the risks associated with going forward.”

The most important message that the Obama administration could send the Iranians—and one, Schiff suggested, that has not yet been fully communicated by the president—is that the U.S. will not fear the consequences of immediately reimposing sanctions on Iran, should Iran be caught cheating. “In the past, the repercussions for Iranian cheating would be that they would have to stop cheating,” he said. “We have to move to a situation in which not all sanctions would be immediately reimposed, but punitive sanctions would be placed on Iran each time there was cheating.”

And what if the Iranians use the reimposition of sanctions as an excuse to void the deal? “Well, then the deal’s over.” He went on: “If we prove they’re cheating, then it’s not the U.S. that is rejecting the deal, it’s Iran that is undermining the deal. We should impose sanctions on them in that case, and also do our best to add new sanctions on top of them. If the sanctions don’t work effectively, then I’m for using force rather then letting them become a nuclear-weapons state. Before Iran crosses the threshold, we would have to stop them by force.”

One of Schiff’s worries earlier this year concerned the reaction of Iran’s neighbors to the deal. If Iran’s various rivals in the region—Saudi Arabia, most obviously—decided that they themselves needed to build nuclear programs to counter their foremost adversary, then the deal would be fatally flawed. “I’m going to be very interested in what the agreement looks like to us, but also what it looks like to people in the area,” he said at the time. “If this agreement is not good enough to keep other nations near Iran from starting nuclear programs— Egypt, Turkey, the Gulf states—if it’s not enough to stop a nuclear-arms race in the region, then we haven’t accomplished very much.”

I asked Schiff what the Obama administration has done subsequently to allay this concern. “I think that if Iran abides by the agreement, and if we take strong action with our Gulf and other allies and constrain Iran’s malicious conventional conduct”— support for Hezbollah, for example —“you won’t see a breakout by these other nations. I don’t think these countries have made a decision to move forward on their own nuclear issues, so it is important that we work with them to counter Iran’s activities. We should rededicate ourselves to making sure that Iranian actions around the region are met by a more than equal and opposite reaction.”

To my surprise, Schiff seemed pleased with the so-called snapback provisions of the Iran deal, which will allow the United States to reimpose sanctions in case of Iranian cheating. Snapback has never been a particularly impressive idea to me, for the simple reason that the reimposition of sanctions after Iran has been allowed to become a far richer country than it is today would have only a limited and delayed impact on Iranian behavior. The release of Iranian funds held in other countries, combined with an inevitable, and possibly imminent, wave of foreign investments, will create for the Iranian regime a substantial financial cushion against future sanctions. But Schiff argued that the growth of the Iranian economy will raise expectations among ordinary Iranians, who will expect their leaders to protect their newfound economic gains. “Will the regime be in a better position to withstand sanctions? Yes. But the regime’s overriding interest is in self-preservation. If they were to cheat on this deal, they would bring down a world of economic hurt again that would send businesses running for the exits.”

Schiff, in our conversation this weekend, did not seem wildly enthusiastic about many aspects of the deal. He said he was disappointed that Iran will not be making a full accounting of its past nuclear-weaponization work—the so-called PMD, or possible military dimensions, issue. “This is an area in which we didn’t achieve as much as we should have.” But Schiff argued that the administration could mitigate the uncertainty surrounding this issue by redoubling intelligence-collections efforts. He is also disappointed, he said, that the deal leaves a substantial number of centrifuges in place. “What concerns me most is the size of the enrichment program that Iran will have in 15 years.”

“We have to make it very clear that we will never tolerate Iran developing highly enriched uranium,” he said.

Perhaps Schiff’s biggest concern, apart from the number of centrifuges Iran will be allowed to operate in 15 years, has to do with the Israeli reaction to the deal. He seemed to be taken aback by the near wall-to-wall opposition of the Israeli political elite to the agreement. “One of the things that has given me the most pause throughout the process is the Israeli opposition across the spectrum. I’ve tried to step back and understand why the perspective is different, and I’ve struggled with this. I’m not sure I can give you the answer.”

But, I asked him, Israeli concerns are not enough to keep you from voting in favor of the deal?

“I don’t think I can substitute anyone else’s judgment for my own. My Israeli friends, and my pro-Israel friends here, are making their points. I have to use my best judgment, and my judgment tells me that we’re better off strengthening the deal than rejecting it. The painful heart of this deal is the trade-off, where Iran has an internationally legitimized and fast enrichment capability, and what we gain in return is at least 15 years in which we’ve cut off any practical path for Iran to a bomb.”

He went on, “The U.S. and Israel share the same imperative: to prevent Iran from getting the bomb. There is not division of interest here. I am comfortable saying that this deal is in the best interest of Israel, as well as the best interest of the United States.”