Trump is expected to announce his decision on the nuclear deal this afternoon, and everyone assumes that he will decide to terminate sanctions waivers and withdraw the U.S. from the deal. Secretary of State Pompeo confirmed as much in a conference call with his European counterparts that the president:

Secretary of State Mike Pompeo told his colleagues from the E3 — France, Germany and the United Kingdom — on Friday that President Trump has rejected the understandings that were drafted with American negotiators over the last four months regarding a possible fix of the Iran nuclear deal.

Ever since Trump delivered his ridiculous ultimatum to our European allies earlier this year, the charade of negotiating a “fix” to a deal that doesn’t need fixing has been an attempt to shift blame for eventual U.S. withdrawal. Instead of simply quitting the deal outright months ago, Trump has feigned an interest in keeping the deal alive when the changes he demanded would have amounted to a violation of it. There was never a chance that France, Britain, and Germany could agree to Trump’s terms without violating their own commitments, and now the charade has finally come to an end.

No one can claim to be surprised that this is how things have turned out. The writing has been on the wall since at least the middle of last year, and Trump made his hatred for the deal impossible to miss during the campaign. Between the constant misrepresentations and lies about the deal from his party’s Iran hawks and Trump’s own ignorance, the deal never stood much of a chance. The fact that it was a major part of Obama’s legacy was probably enough by itself to ensure that Trump would reject it. That is what made the charade of trying to “fix” the deal so absurd, since it was obvious that Trump had already made up his mind about it long ago.

All of the other parties to the agreement have expressed their desire to keep it alive even without U.S. participation. If the Trump administration is intent on reimposing sanctions and enforcing them, that sets the stage for an unnecessary and destructive fight with the EU. Reneging on the deal drives a wedge between the U.S. and Europe that harms relations with our allies for no good reason, and it will likely make our allies think twice before they support another major U.S. diplomatic initiative.

Iranian hard-liners will be pleased by Trump’s decision, since it lets them claim vindication and accuse their domestic opponents of making the mistake of trusting the U.S. Hard-liners in the U.S. and Iran feed off of each other, and when they are in the ascendant in one country it boosts hard-liners in the other. Armed conflict between U.S. forces and Iran and its proxies is going to become more likely as a result of this decision, and that could escalate into a larger war faster than anyone expects. Once the U.S. is out of the deal, it won’t be long before we hear the usual drumbeat for military action against Iran.

Reneging on the nuclear deal doesn’t serve any American interests and does significant harm to several of them. Other states will be less willing to trust the U.S. to honor its obligations. That will raise the costs of every negotiation the U.S. conducts with other governments during the current administration. Every government that cooperated with the U.S. to secure the deal will remember how Trump simply threw away a major diplomatic achievement for the sake of spite and ideology, and they will be less inclined to cooperate with Washington the next time their help is needed.

Withdrawing from the JCPOA is a huge unforced error and self-inflicted wound whose full costs we won’t realize until later, and it represents a serious setback to the cause of nonproliferation. Trump is walking away from a deal that got the U.S. almost everything it wanted at virtually no cost, and he is doing it mainly because it allows him to repudiate his predecessor’s work. It is a perfect example of putting petty self-interest and pique ahead of the interests of the United States, and it has absolutely nothing to do with putting America first.