The international agreement to restrain Iran’s nuclear program, which will likely go into effect next week, should count as the crowning diplomatic achievement of Israeli Prime Minister Benjamin Netanyahu. The ratification of this deal marks the first time Iran has agreed to radically curtail its previously unregulated nuclear activities, and it would not have happened without Netanyahu.

For more than a decade, he has lobbied, cajoled, and pressured the United States and Europe to thwart Iran’s nuclear ambitions. He played by far the largest role in focusing the attention of the great powers on the threat of a nuclear Iran. His single-minded, insistent lobbying, his powerful speechmaking, and his orchestration of a highly potent publicity campaign in Washington, when combined with the presence, in the White House, of a president predisposed to believe that a nuclear-armed Iran would pose a profound national-security threat to the U.S. (I am not referring here to George W. Bush), led to the application of crippling, multilateral sanctions on Iran, a sanctions regime that brought Iran to the negotiating table. At the negotiating table, Iran’s leaders eventually agreed to a set of limitations and controls on the country’s nuclear program that are quite stringent, and which, if properly implemented, reduce the chance that Israel will find itself the target of an Iranian nuclear weapon for many years to come. And all this was achieved without preventative military strikes that might have delayed, but not prevented, Iran from crossing the nuclear threshold. Of course, the threat of a unilateral Israeli strike on Iran’s nuclear facilities—a threat deemed credible by the Pentagon, by the White House, and by many European leaders—also helped concentrate the world’s attention on the problem, and aided President Barack Obama in his campaign to convince sometimes-balky allies to join in the sanctions regime in order to prevent an Israeli strike.

Netanyahu, of course, doesn’t see this agreement as a victory for Israel; he sees it as a victory for evil, and as a bitter defeat for the once-great United States of America. The reason Netanyahu believes this agreement represents a defeat for the U.S., and an existential threat to Israel, is not because of weaknesses in any of its specific provisions, singly or in combination. The deal is far from perfect. All arms-control agreements are the products of sometimes discomfiting compromises, and this one has its fair share of problems, not least of which is that it comes with an end date.

Netanyahu’s complaint is not with the Iran deal. It is with the notion that one can deal with Iran. Like many of his Republican allies on Capitol Hill, he sees this deal as a defeat because it brought about neither complete capitulation by Iran at the negotiating table nor the demise of the Iranian regime. Netanyahu’s worldview is Manichaean; there is good, there is evil, and good people don’t do business with evil. I have sympathy for this view; I am a Reform Manichaean myself, and I think I understand the perfidious nature of the Iranian regime. But the total defeat of Iran was not a credible option, especially in the post-Iraq War American political reality, and it was Netanyahu’s mistake—one of several mistakes—to believe a) in the lethality of sanctions that turned out to be merely crippling, and b) that the United States, in the absence of sanctions-induced regime change, would choose confrontation over diplomatic compromise.

I framed the first paragraph of this post in a way meant to highlight a public path Netanyahu could have chosen in the months before the nuclear agreement was finalized. Imagine, for a moment, if, instead of committing to a public fight with the chief executive of the nation that is Israel’s benefactor—a fight, for reasons I will soon explain, Netanyahu was never going to win—he had instead done the following: claimed victory in his struggle to keep Iran away from the nuclear threshold, and then announced that he would be working with Obama and his European allies (and with Vladimir Putin as well) to ensure that the deal was as tough as possible. Would he have gotten all, or even much, of what he wanted? Probably not. But would the deal be somewhat stronger today if Netanyahu hadn’t made the perfect the enemy of the good? Yes, most likely.

It was not only Netanyahu’s Manichaean worldview that placed him on the path toward a fruitless, even self-destructive, confrontation with Obama (and the rest of the world); it was his faulty understanding of American politics. Specifically, he made three basic mistakes of analysis:

1. He overestimated the power of AIPAC, the main pro-Israel lobbying group, to fight a president deeply committed to the idea of a deal;

2. He underestimated just how alienated many Democrats in Congress, including (and, in some cases, especially) Jewish Democrats, felt about his leadership, and in particular his decision to make Iran a partisan issue in Washington;

3. He did not understand that post-Iraq fatigue in America created more space than usually exists for diplomacy with a rogue regime.

It is Netanyahu’s Manichaean worldview that moved him to make confronting Iran the cause of his life, and he succeeded beyond expectation in pressuring the international community to extract significant concessions from his foe. But it is this same black-and-white view of the world that kept Netanyahu from participating in the shaping of the final deal—to Israel’s detriment, alas—and this same worldview that prevented him from claiming victory, when victory was his.