As Congress debates the agreement with Iran, there will be much bluster in the next couple of months about bomb grade fuel, breakout times, centrifuges, heavy water reactors, stockpiles of enriched uranium, and, of course, the impediments to inspection. But all this technical stuff will have nothing to do with what really bothers the most blustering of the nay sayers.

In their view, we had the Iranians down. It hurt so bad they were screaming for us to let go. And now, for a bunch of promises, we are letting go. Soon they will bounce up, stronger than ever and just as defiant. That is why Jeb Bush and others are damning the agreement as appeasement. That is why Prime Minister Netanyahu condemns it as an historic mistake. In their view, we should keep the Iranians down and let them scream, try hurting them more, not less. That’s what you do with evil.

It is a visceral feeling that has nothing to do with centrifuges and enrichment and all the other details of the agreement. Even if Iran had given up all centrifuges and all enriched uranium and let us obliterate their nuclear facilities and inspect them up and down at any time forever, the critics would find some pitfalls in the agreement, some red line that Iran was allowed to cross. Sanctions have weakened Iran, and, in the view of the opponents, lifting sanctions will renew the strength of Iran and allow it to terrify others with impunity.

This kind of confusion and fury over the lifting of sanctions is not new. Something similar took place at the end of the first Persian Gulf War in 1991 when the United Nations subjected Iraq to what was known as the mother of all sanctions. The sanctions were supposed to vanish when UN inspectors declared Iraq free of nuclear and other weapons of mass destruction. But the George H. W. Bush Administration and all others that followed made it clear that the United States would never allow the lifting of sanctions so long as Saddam Hussein remained as ruler of Iraq.

American policymakers had every right to expect Saddam to fall soon. Rulers usually fail to survive massive defeats. Emperor Napoleon III lost his crown after the defeat of France in the Franco-Prussian war of 1870. So did Kaiser Wilhelm II after the defeat of Germany in World War I. But Saddam maintained his dictatorial rule. Since the Americans insisted that sanctions now depended on his departure, Saddam played games with the inspectors, letting them in but throwing them out every few months. He even boasted about the weapons he did not have. The George W. Bush administration was so sure of his stockpiles that Vice President Dick Cheney warned inspector Hans Blix of Sweden that the administration was “ready to discredit inspections in favor of disarmament.” In short, failure to find the weapons would only be used to prove the incompetence of the inspectors. President Bush did not wait for the final reports of the inspectors before invading. No weapons of mass destruction were ever found. The war was such a debacle — plunging Iraq into chaos, expanding the influence of Iran, and birthing the terrible Islamic State — that the whole adventure would be laughable if 4,500 Americans and several hundred thousand Iraqis had not died. The invasion of Iraq is hardly an advertisement for inflating the rationale of sanctions.

For the most part, the foreign policy establishment — former ambassadors, former State Department officials, non-partisan think tankers — supports the agreement. The agreement has demonstrated that sanctions work when applied for a limited cause. Sanctions would surely have withered in time if the rest of the world felt the United States was unfairly raising the price for relief. The agreement also has paralyzed the Iranian drive for a nuclear weapon for at least ten years and given the United States a full year to respond should Iran begin to cheat. All in all, the agreement is a brilliant diplomatic achievement. As President Obama has pointed out, it does not turn Iran into a peaceful and democratic ally. But that, after all, was not the aim of the sanctions and the diplomacy.

On top of this, as Secretary Kerry insists, all options remain if Iran decides to cheat. I suspect that snapping sanctions back on will be more difficult than it sounds, for some governments may hesitate about giving up their renewed trade. But the United States will still maintain that it has the right to bomb Iranian military installations if that is the only way to stop production of a nuclear bomb. The biggest problem, in fact, may involve dealing with unreasonable demands for bombing from critics who exaggerate the slightest Iranian hesitation or misstep into a trigger for war.

Logic and good sense are on the side of the agreement. But logic and good sense do not always prevail in American politics.