Enforcement is absolutely essential here. The deal itself is only as good as what it prevents, and if it doesn't prevent Iranian nuclear expansion, then it's a problem, and it isn't as worth preserving at that point.
I think the real issue is that no one has yet shown me, anyway, anything with confidence that says we'll get the same positive result with regard to Iran's nuclear program without having the JCPOA. I think my biggest fear is that we'd be jettisoning something that's working even if there are some implementation issues that, again, are fairly reserved in their consequence. I mean, a little bit too much heavy water in Iran's current nuclear context is fairly insignificant towards the nuclear weapons purpose and far less significant than what they might do if the Iranians have to back out of this.
I think, ultimately, the real issue with the JCPOA is that it was always going to be a fairly tentative agreement since there wasn't buy-in by all the various different factions of all the various different parties. It was most pronounced in Washington and most pronounced in Tehran. The degree to which hardliners in both capitals are of the same mind, looking at one another, and seeing nothing but hostile intent, I think, has been very damaging to the JCPOA. This is why compliance thus far has been so important, and I think that the degree to which Iran has complied, and they have, and the degree to which we've complied on economic relief, and we have, is a positive. I think it will give the Iranians pause before they think about backing away from the deal on their own. My hope is that Washington has the same sort of pause now when it considers what the risks are.