The Legality of Attacking Iran
Necessity and proportionality are the essential principles of self-defense. The rest is nonsense.

Yale law professor Bruce Ackerman


As the drumbeat for strikes on Iran’s nuclear facilities grows louder, attention has begun to focus on the key international-law question: Would such strikes be legal? Many conservatives tend to think that international law doesn’t matter, because we know we’re right and international law is just another fiefdom of clueless liberal academics.

Both of those things are true, but that doesn’t mean we can ignore the issue of legality. The reason is strategic. International law supplies the terms of diplomatic debate, which in turn shapes public discourse, which in turn determines the degree of public support for a war policy. In a democracy, politics constrain the range of choices available to leaders. That is how international law affects the effective reach of strategic power.

Given the importance of the legal question, the cacophony of recent commentary — on both sides of the issue — is a clear sign of big trouble ahead.

In the L.A. Times, Yale law professor Bruce Ackerman argues that strikes on Iran’s legal facility would violate international law, because Iran has not attacked us and there is no “imminent” attack. On the Corner, David French and Jay Sekulow take aim at Ackerman’s argument by pointing out that Iran has already “attacked” both the U.S. and Israel through proxies, so there’s no need to wait for an “imminent” attack. Writing on Real Clear Politics, Peter Berkowitz takes a different tack, noting that the Obama administration has already called for “a more flexible understanding of ‘imminence’” in a reprise of the Bush administration’s National Security Strategy.

The argument that Iran has already attacked both the U.S. and Israel is not convincing, because even if Iran had attacked nobody, the danger posed by its nuclear program would now be precisely the same. Iran’s open belligerence has helped to unify world opinion against the mullahs and their nuclear program, providing a political defense, but it doesn’t make a clear-cut case of why we should have the right to attack its nuclear program.

As can be expected for just about any argument he weighs in on, Berkowitz has the better of this one. But his take is not entirely satisfying, either. He gives several examples of why preemptive attacks against Iran’s program are justifiable on the basis of necessity. But simply positing that, given the capabilities of modern states, necessity justifies “a more flexible understanding” of what constitutes an imminent threat still does not spell out a clear principle of law.

Everyone seems to agree that preemption is justified to forestall an “imminent threat.” But that term conflates two very different concepts: imminent attack and immediate threat. The 1994 North Korea nuclear crisis is a perfect example of how you can have the latter without the former. North Korea’s move to discharge plutonium-laden fuel rods from the reactor core at Yongbyon represented the last point in time when its program could be interdicted with confidence. That’s why President Clinton nearly decided to bomb the reactor. Even though a North Korean nuclear weapon — and therefore an imminent attack — would still be years away at the earliest, the North Korean move represented such a deterioration in the status quo, with so many possibly catastrophic consequences, that it presented an immediate threat.

Indeed, Clinton’s reckless decision not to bomb the Yongbyon reactor gave Iran a vital green light at an early stage. That green light has been sustained by Security Council resolutions that, despite some effectiveness, have forecast to Iran that we are not threatening strikes in the near term.

Ackerman concedes Berkowitz’s basic point, that customary international law allows the preemption of an imminent attack. He harkens back to a 19th-century dispute which arose when the British destroyed an American vessel, the S.S. Caroline, that had helped ferry aid to rebels in Canada. Secretary of State Daniel Webster demanded an explanation of the legal basis for the British attack. He insisted that in cases of preemptive self-defense, the “necessity of self-defense” must be “instant, overwhelming, leaving no choice of means, and no moment for deliberation.”

Any law student who takes a class on international law will soon find himself confronted with the colorful exchange of diplomatic letters known as the Caroline dispute. It is the case most often cited for the proposition that international law allows preemptive self-defense in case of an imminent attack. But the key word in Webster’s formulation is almost always ignored: necessity. I disagree with Berkowitz on this narrow point: We don’t need a more flexible approach to “imminence,” a concept that only confuses the issue. What we need is a renewed focus on “necessity.”