As it keeps making its case for an attack on Iran's nuclear facilities, Israel isn't being very subtle: Iran will have a nuclear bomb, possibly as early as this year, its leaders suggest; Iran's leadership is suicidal it will drop a nuclear bomb on Israel given the opportunity. So how, the Israelis then ask, can we not afford to destroy Iran's nuclear facilities, as we did Iraq's in 1981?
Such stark, simplistic logic appeals to Prime Minister Benjamin Netanyahu, but it skirts a couple of key questions about any such attack. For starters, would it actually succeed in putting a halt to Iran's nuclear program? Leadership at the Pentagon appears to think the answer is no. But what Israel and few others talk about, or not convincingly at least, is the other very risky unknown about such a strike: how exactly Iran would respond to it. Speculating a few weeks ago, Chairman of the Joint Chiefs of Staff Mike Mullen told the Wall Street Journal that Iran's ability to strike back "has not maxed out at all." Mullen doesn't offer specifics but leaves the impression that Iran will do what it has done in the past: small-scale attacks on U.S. troops in Iraq and Afghanistan, and Hizballah and Hamas rocketing of Israel. But as bad as that would be, what if Iran is preparing for a much broader response, even a full-fledged war? (See pictures of Iranian President Mahmoud Ahmadinejad.)
In fact, that is exactly what Iran's hard-liners have in mind. Over the past five years, in public and in government documents, the hard-liners have established a doctrine of deterrence that calls for a disproportionate response against the U.S. and Israel in the event of any attack on Iran's nuclear facilities, no matter how limited. The doctrine stipulates that anything less than a large-scale response would risk the credibility of the Iranian regime and its survival. And importantly, it does not draw a distinction between Israel and the U.S., if for no other reason than Israeli jets have to fly across U.S.-controlled Iraqi airspace to hit Iran.
Iran's deterrence doctrine is largely authored by the nation's Islamic Revolutionary Guard Corps, a wing of Iran's military charged with the protection of the regime. The doctrine is grounded in Iran's experience and study of four wars: the Iran-Iraq war (1980-88), Hizballah's war against Israel (1982-2000 and 2006), the Gulf War (1991) and the Iraq war (2003).
Iran's deterrence doctrine consists of four components:
1) The U.N., including the International Atomic Energy Agency, cannot deter an attack on Iran no matter the degree of Iran's openness or compliance on nuclear inspections. Saddam Hussein cooperated with the U.N. and rid himself of weapons of mass destruction, but in the end it did nothing to stop a U.S. invasion. Submission to a strict U.N. monitoring regime will only serve to degrade Iran's national security.
2) Iran will fight the war against Israel and the U.S. outside Iran's border, and Iran alone must determine the area of operations. Saddam lost his country and his life because he chose to resist the U.S. within Iraq's borders. Iran will respond to an Israeli attack by attacking the U.S. and its allies in Iraq, Afghanistan, Lebanon, Gaza, the West Bank and the Persian Gulf countries. Just as Iran makes clear with bellicose threats by President Ahmadinejad that it would destroy Israel if the U.S. launched an attack, it aims to deter an Israeli attack by stressing the price U.S. forces would have to pay in return.
3) The Iranian regime is capable of sustaining massive U.S. reprisal attacks without falling. In 1991 Saddam's army suffered a catastrophic defeat with the backbone of its army and air force destroyed and the loss of much of the southern part of the country to Shi'ite insurgents, but Saddam held on and remained in power. The Iranian regime believes it can weather the same degree of losses, especially as it has adequately prepared its populace for "martyrdom." As a result, it believes it is able to withstand much greater human and material losses than the U.S. A $100-per-bbl. spike in the price of oil and a few thousand Americans dead, its thinking goes, will convince the U.S. to seek a truce.
4) It is well-prepared for a long, costly war. Iran learned how to fight an asymmetrical guerilla war in the 1982-2000 conflict in Lebanon, learning that lightly armed, small, mobile units can beat a larger enemy. Secondly, Iran knows it needs to eliminate any potential fifth column. Saddam's failure to destroy the Iraqi opposition, in particular the Kurdish groups in the north, called into doubt the Iraqi regime's legitimacy. It facilitated the notion that the Iraqi people had asked for a foreign invasion to deliver them from Saddam. Iran's crackdown on student dissidents, foreign journalists and dissident political movements should be viewed in this context.
Not all Iranians, of course, agree with the hard-liners' deterrence doctrine, but they do not have a voice in Iran's national security. Iran's Supreme Leader Ayatullah Ali Khamenei, the Revolutionary Guard and other hard-liners alone determine Iran's national-security policies. And as Israel and the U.S. calculate the cost of attacking Iran's nuclear facilities, they should realize that the decision makers inside Iran have no thought of a limited response.
Baer, a former CIA field officer assigned to the Middle East, is TIME.com's intelligence columnist and the author of See No Evil and, most recently, The Devil We Know.
Bastani is a member of the editorial board of the Iranian daily Rooz Online.