NEW YORK — At the heart of the concerns surrounding the deal with Iran is a simple question: Is Iran rational? The answer for many critics of the deal is self-evident. The Iranians are “apocalyptic,” Israeli Prime Minister Benjamin Netanyahu has often said, warning that you can’t “bet on their rationality.” Sen. Lindsey Graham says “I think they’re crazy.” The Iranian government, Israeli Defense Minister Moshe Yaalon reaffirmed recently, is a “messianic and apocalyptic regime.”

And yet, these same critics’ preferred policy is one that relies on Iran’s rationality. The alternative to the deal forged by Iran and the six great powers is not war, they insist, but rather to ratchet up the pressure and demand more concessions from Tehran. So, this crazy, apocalyptic band of mullahs will, when faced with a few more sanctions, calmly calculate the costs and benefits and yield in a predictable way to more pressure. Or as J.J. Goldberg writes in the Forward, “Apparently they’re irrational enough to welcome nuclear Armageddon, but rational enough to yield to economic punishment.” (This point is also well made by Vox.com’s Max Fisher.)

In fact, in his thorough book, “Unthinkable: Iran, the Bomb, and American Strategy,” Kenneth Pollack carefully reviews decades of Iran’s foreign policy and shows that it has been not just rational but prudent, pushing forward when it sees an opportunity, backing off when it sees dangers. He quotes a former Israeli armed forces chief of staff who explained: “The Iranian regime is radical, but it’s not irrational.”

Rational does not mean reasonable. It means that the regime wants to thrive and, given that goal, it calculates costs and benefits and acts accordingly. But it is worth asking a broader question as well: Is Iran being reasonable? Are Tehran’s actions an understandable response to its geopolitical situation? At a Time Warner public conversation last week, former Secretary of State James Baker remarked that the key to success in negotiations is to put yourself in your adversary’s shoes and see the world from that perspective.

Look at a map of the Middle East. Shiite Iran is surrounded by hostile Sunni states. Across the Persian Gulf sits Saudi Arabia, its archenemy, fanatically anti-Shiite and armed to the teeth. (In 2014, Saudi Arabia was the largest weapons importer on the planet.) In Iraq and Syria, Iran faces large Sunni insurgencies dedicated to slaughtering the Shiites. Add to this the nuclear dimension. Iran has several nuclear-armed neighbors — Pakistan, India, Russia, China and Israel.

Plus, Iran has faced active opposition from the world’s superpower for more than three decades. When Iraq attacked Iran shortly after the Islamic revolution, the United States quietly supported Saddam Hussein, even as he used chemical weapons against the Iranians.

Seymour Hersh has reported extensively for The New Yorker on America’s covert support for groups within Iran that seek not only to topple the regime but also dismember the country. Some of these groups, like the Mujahedeen-e-Khalq and Jundallah, are regarded by some as pretty nasty terrorist outfits. For a decade starting in 2001, Tehran watched as 200,000 American troops massed across its eastern and western borders in Iraq and Afghanistan. The Bush administration openly talked about the need for “regime change” in Tehran, which was branded as part of the globe’s “axis of evil.”

I am not making the case that any of these policies should have been altered — international politics is a rough business — but given these realities, is it so bizarre that Iran has behaved as it has? Or that it has sought to build a nuclear industry that could give it a pathway to a nuclear weapon? Would a secular, hyper-rational country facing this same array of threats have acted differently?

In 1963, John F. Kennedy predicted that the world would see 15 to 25 new nuclear-armed states within a decade. The reason he made that statement was that back then, nuclear technology was something any country with a serious industrial and scientific base could develop. (Which is why India and Pakistan were able to go nuclear in the 1970s.) Today this is even more true. Nuclear fission is not some cutting-edge 21st-century technology. It is now 70 years old, part of the era of black-and-white television.

Kennedy’s prediction has not proved true because the international community, led by the United States, has confronted nuclear wannabes with real costs but also benefits. (Even Moammar Gadhafi only gave up his nuclear program after years of threats when he was finally given some positive incentives to do so as well.) The Lausanne framework appears to strike that balance for Iran. There is no guarantee that its supreme leader will accept the trade-offs — as his recent tweets remind us — but the offer forces him to make a rational calculation and live with the consequences.

Fareed Zakaria is a syndicated columnist. His email address is: comments@fareedzakaria.com.