PARIS—Listening today to President Donald Trump destroy the accord with Iran that had frozen its nuclear program, it is hard for anyone who watched the run-up to the Iraq War (2003- ) not to hear echoes of that sorry past.

The fact is, the Bush administration built the most compelling part of its case for the invasion of Iraq not on what it knew, but on what it did not know. And that is the path we are headed down again.

Consider National Security Advisor Condoleezza Rice’s all-too-quotable remark to CNN in September 2002: “The problem here is that there will always be some uncertainty about how quickly he [Saddam Hussein] can acquire nuclear weapons. But we don’t want the smoking gun to be a mushroom cloud.”

That, in turn, was based on the surreal logic of Defense Secretary Donald Rumsfeld a few weeks earlier. He’d been asked an obsequious leading question about Saddam’s WMD and links to terrorists: were they worse than many analysts thought?

“There are things we know that we know,” said Rumsfeld. “There are known unknowns. That is to say there are things that we now know we don't know. But there are also unknown unknowns. There are things we do not know we don't know.”

A few weeks after the invasion, when it was obvious Saddam would have used his WMD arsenal if he had one, rather than face the massive defeat that was handed to him, Richard Haass, who was then at the State Department, confirmed at a press briefing that the U.S. had, indeed, gone to war because of what it did not know. But by then more than 1,000 Americans had fanned out across Iraq looking for the weapons that didn’t exist.

“ In just a short period of time, the world’s leading state sponsor of terror will be on the cusp of acquiring the world’s most dangerous weapons. ” — President Donald Trump, 2018

Why was the United States so ignorant that it felt it had to invade another country just to be sure it could be safe? To paraphrase an old saying: none so blind as those who blind themselves.

That is exactly what Trump is doing, and one marvels at his oblivious belief that with his self-advertised “art” as a dealmaker he can extract something bigger, and better, and safer, and surer than the current arrangement.

The strongest aspect of the Iran deal negotiated by the Obama administration—and Great Britain, France, Russia, China, and Germany—is not just the reduction and elimination of fissile materials and the freezing of Iran’s nuclear program until 2025, it is the extensive inspection regime to which Iran agreed .

Without those inspections—and they are very likely to end sooner rather than later now that Trump is out to kill the deal—then the United States will be just about as ignorant of what goes on inside the Islamic Republic as it was about the situation in Iraq in 2002. Or, for that matter, as previous administrations were when North Korea kicked out inspectors and, yes, wound up a few years later as the nuclear weapons state that is today.

“Iran will have no reason to allow inspectors into the country and we will lose important insight into their future actions,” says former CIA military analyst Cindy Otis. “We have lifted the one constraint on their activities. Sanctions were not an effective measure to curbing their activity in the past, otherwise we wouldn't have needed the deal to begin with. Iran has said they can pick up where they left off in developing nuclear weapons and we have forfeited our access and insight.”

None of this is to say that there are not a host of issues that need to be addressed with Iran.

Now, as in 2002, it is easy to recite a litany of the enemy’s crimes. Iraq’s Saddam Hussein was a dictator about as evil as they come. U.S. President George W. Bush likened him to Hitler. And today the mullahs and Revolutionary Guards of Iran are threats on many fronts, particularly in the region. Over the years they have indeed sponsored terrorist attacks around the world, they are developing ballistic missiles, and they are growing their military presence across the Middle East, sometimes putting their own boots on the ground, more often using proxies. Trump is not wrong about all that.

But by ditching the present arrangement, which he seems to hate not least because it is part of the Obama legacy, and which he promised his faithful followers he would tear up, Trump will only destabilize the region further. His encouragement of regime change will act as an incentive to those in Iran who want a tighter lid on society, and an ever more powerful military, and perhaps nuclear weapons. And to justify all this, what logic does Trump use?

“ We don’t want the smoking gun to be a mushroom cloud. ” — National Security Advisor Condoleeza Rice, 2002

"If we do nothing, we know exactly what will happen," Trump told the world today. "In just a short period of time, the world’s leading state sponsor of terror will be on the cusp of acquiring the world’s most dangerous weapons."

You'd think he had some of he same script writers as Bush... Wait. Wasn't John Bolton, the new national security advisor, the under-secretary of state for arms control back in 2002? Ah, yes. "There is no doubt in our mind that Saddam Hussein has an active chemical and biological warfare effort," he proclaimed in November that year. "The evidence is there—the question is whether the inspectors are allowed to find it."

One of the more bitter ironies in the history of the Iraq debacle is that even before Bush, the Clinton administration, frustrated by Saddam’s efforts to confuse or thwart U.N. inspectors, told them to get out at the end of 1998 and proceeded to bomb the hell out of Iraq for four days in what was called “Operation Desert Fox.”

That accomplished nothing but the inspectors were not allowed back, and for four years after that U.S. intelligence about Saddam’s weapons programs essentially went dark. The known knowns became unknowns.

Then, in 2002, under threats of war led by the Bush administration, Saddam let inspectors back in and allowed them to visit every corner of his country, including his palaces. By early 2003, the problem the Bush administration faced was not that Saddam had not cooperated with the inspectors, but that he had. And they found nothing.

That could have been a good reason not to go to war. But the Bush administration at that point did not care that no nukes were discovered, and for that matter no chemical or biological weapons either. So it accepted the lies of dubious sources as "slam dunk" truths. The bottom line was that the Bush administration convinced itself, and much of the press and public, that Americans could never be safe until all the unknown unknowns were taken care of. And that is precisely what Trump is trying to do now.

Today, as France, Britain, Germany and anyone familiar with the region has made clear, it would have made infinitely more sense to keep a deal with Iran that exists, a bird in the hand, as it were, rather than to go down the road that Bush did. But Trump, keeping a promise to his core supporters, thinks he knows better.