For the past year or so, in speaking to groups, I’ve ventured to suggest that Donald Trump will ultimately rank among the least consequential presidents in U.S. history. I did not intend that to be a laugh line.

Trump, I argued, was likely to end up being to the 21st century what James Buchanan was to the 19th and Warren G. Harding to the 20th – someone who, after occupying the White House for a time, departed and left nary a trace. In the end, Trump’s defining traits — vulgarity, meanness, self-absorption, and apparently compulsive dishonesty — would count for little in the scales of history. So I believed.

Let me confess that I have now begun to entertain second thoughts. Trump’s abrogation of the Joint Comprehensive Plan of Action, the so-called Iran deal, easily qualifies as the most consequential decision of his administration. For once bluster is matched by action. Trump appears intent on making his mark after all.

In reaching this decision, Trump ignored the advice – make that, pleas – of traditional U.S. allies such as France, Germany, and the United Kingdom. Instead, the president chose to heed the counsel of his new friends Saudi Crown Prince Mohammed bin Salman and Israeli Prime Minister Benjamin Netanyahu. Viewed from this perspective, May 8, 2018 marks the inauguration of a Saudi-American-Israeli axis and a major realignment of U.S. strategic relationships.

The creation of this new partnership confirms the fact that NATO no longer constitutes the central pillar of U.S. national security policy. Dating from its creation back in 1949, the purpose of the now essentially defunct Western alliance was to contain the Soviet Union, prevent war, and nurture liberal democratic values. Today the USSR is long gone. And if the West still exists, it no longer really matters, at least in Trump’s estimation.

In contrast, the not-quite-explicit purpose of the new Saudi-American-Israeli axis is not to contain the Iranian government, or “regime” in Trump-speak, but to overthrow it. Indeed, there is ample reason to suspect that Trump and those to whom he looks for advice would actually welcome a war against Iran.

No doubt MBS fancies that such a war will elevate Saudi Arabia to a position of preeminence in the Gulf. For his part, Netanyahu probably fancies that toppling the mullahs in Tehran will enhance Israeli security. There may even be some basis for their views. One can easily imagine the two of them this very day figuratively raising a glass to their pliable pal in the White House. Here’s to you, Mr. President!

How engineering regime change in Tehran will benefit the United States is less clear. This is especially true if taking into account the results of America’s “success” in overthrowing governments in Afghanistan, Iraq, and Libya since 9/11. The facts speak for themselves: When U.S. forces oust an undesirable government in the Islamic world, the inadvertent result is to make things worse. Been there, done that, several times over. 

Yet here’s the irony: As a candidate for president, Trump seemed to understand that U.S. military interventionism in the Middle East had exacted huge costs while accomplishing next to nothing. If elected, he was going to extricate the United States from endless war. Now, Trump is deep-sixing one of the few glimmers of hope that the United States might some day extricate itself from the mess that it has done so much to create. Instead, apparently egged on by the likes of Secretary of State Mike Pompeo and national security adviser John Bolton, the president has decided to continue the futile and counterproductive effort to assert hegemony in the Greater Middle East. 

How will this decision effect the other signatories of the JCPOA? If the Russians and Chinese are smart, they will stick to the terms of the agreement, demonstrating the maturity and consistency that are marks of a mature power. In other words, by doing nothing, they can win big points at Washington’s expense.

How France, Germany, and the United Kingdom will react is the more interesting question. For years now, the United States has verged on going rogue – recall, for example, George W. Bush’s thumbing his nose at the world in deciding to invade Iraq in 2003. Now it has definitively done so. If the European democracies pretend that Trump’s highhandedness is nothing out of the ordinary, they will forfeit whatever last remnants of political credibility they possess.

By and large, I dislike Munich analogies. But in this instance the comparison may have some merit. In 1938, faced with a megalomaniac in charge of a fearsome military machine and surrounded by a coterie of fanatic militarists, the European democracies wilted, paving away for a great disaster. Today another megalomaniac with a fearsome military machine at his command and responding to the counsel of the latter day equivalent of Goering and Goebbels is on a tear. History will not treat European leaders kindly if they repeat the mistakes of Neville Chamberlain and Eduard Daladier. As an American, I believe that Trump needs to be confronted, not indulged.

“When I make promises, I keep them.” So Trump stated while announcing his decision to withdraw from the JCPOA. Well, no, Mr. President you don’t, as your several wives and sundry business associates can attest. Your modus operandi is betrayal.

The abandonment of the JCPOA is an act of betrayal with global implications. Who will say nay?

Andrew J. Bacevich is author of America’s War for the Greater Middle East: A Military History.