In an interview with Jeff Goldberg late last week, President Obama stated that a U.S. “military component” was on the table in response to Iran’s nuclear threat, and added that “as president of the United States, I don't bluff." Peter Berkowitz has a pithy essay that makes what is to my mind a persuasive case for the legality under international law of such a preemptive military strike. The key legal argument:
The charter of the United Nations affirms member states’ obligation to refrain “from the threat or use of force against the territorial integrity or political independence of any state” and, while envisaging a vigorous role for the Security Council in managing the use of force, also affirms states’ “inherent” right of self-defense.
States need not absorb a blow before they resort to military action. When threats are imminent, customary international law recognizes a right of anticipatory self-defense, though of course its scope is disputed.
Authority can be found for both a narrower and broader reading of imminence. In the “Caroline affair” of 1842, U.S. Secretary of State Daniel Webster, advancing the most stringent interpretation of imminence to make the case against the destruction by the British in 1837 of an American steamer, argued that states which have claimed a right to strike first must be able to “show a necessity of self-defense, instant, overwhelming, leaving no choice of means, and no moment for deliberation.”
But as Yale historian John Lewis Gaddis shows in “Surprise, Security and the American Experience,” the United States has been claiming the right to use force against emerging threats since 1818, when John Quincy Adams, President James Monroe’s secretary of state, formulated the doctrine to justify Gen. Andrew Jackson’s raids into Spanish Florida. Long after Webster settled the Caroline affair amicably, Presidents Theodore Roosevelt, William Howard Taft, and Woodrow Wilson all argued that the United States had a right to use force against failed or rogue states whose conduct endangered international order, and all ordered American troops into action on that ground.
In immediate response to al-Qaeda’s Sept. 11 surprise attack, but also in view of the steadily increasing threat posed by the proliferation of weapons of mass destruction, the Bush administration’s 2002 “National Security Strategy of the United States” argued for a broader reading. It maintained that the use of preventive force would sometimes be necessary because of “the inability to deter a potential attacker, the immediacy of today’s threats, and the magnitude of potential harm that could be caused by our adversaries’ choice of weapons.” The failure of coalition forces to find weapons of mass destruction in Iraq after the American-led 2003 invasion does not affect the logic of the argument, even as it underscores the dependence of strategic judgments on sound intelligence.
In a September 2011 speech at Harvard Law School, John Brennan, the Obama administration’s top counterterrorism adviser, effectively embraced the Bush administration’s broader interpretation by calling for “a more flexible understanding of ‘imminence.’ ” To be sure, Brennan was discussing terrorist organizations. But the logic of his contention that the understanding of an “ ‘imminent’ attack should be broadened in light of the modern-day capabilities, techniques, and technological innovations” applies equally to rogue states.
The key factual assumption:
Because even a single nuclear weapon can inflict horrific damage and deal a small state like Israel a crippling blow, because of the variety of quick and covert ways Iran and its terrorist proxies have for delivering such a weapon, and because their brand of radical Islam undercuts the assumptions on which our cold war models of deterrence rest, Israel’s right of self-defense extends to preventing Iran from acquiring nuclear weapons.
Under international law, the right of self-defense encompasses a right to assist others to defend themselves. Israel’s vulnerability to surprise and devastating attack by a nuclear-armed Iran and its terrorist partners permits the United States, whose capacities to search out and destroy Iran’s nuclear facilities considerably exceed those of Israel, to also lawfully use force to prevent Iran from acquiring nuclear weapons.
Berkowitz ends with the important caveat that "not everything that is lawful is prudent and wise."