International law is not a suicide pact. Fashioned to ensure the survival of states in a world still lacking global government, these binding rules emphasize the right of national self-defense. This right may be exercised not only after an attack has already been suffered, but also in advance, if the defensive first strike can meet certain essential conditions.
Consider Iran. President Bush has assuredly authorized the Pentagon to prepare plans for the pre-emptive destruction of that country's developing nuclear installations. Leaving aside the difficult tactical side of such an operation -- and whether or not it would actually be helpful to American national security -- a prior question arises: Would this particular pre-emption be permissible under international law? Although similar legal questions have been raised about the current war in Iraq, a defensive first-strike against Iran would have far narrower strategic goals. Here, with no obvious humanitarian intention of regime change, America's only verifiable target objectives would be specific nuclear industries and infrastructures.
Pre-emption, of course, is already a codified part of Mr. Bush's military doctrine. Operation Iraqi Freedom is rooted conceptually in "The National Security Strategy of the United States of America" (Sept. 20, 2002), a document which recognizes explicitly the customary right of "anticipatory self-defense" under international law and which expands this right under American legal practice. But what do we really know about anticipatory self-defense? International law has multiple authoritative sources, including international custom. Although the written law of the U.N. Charter reserves the right of self-defense to states that have already suffered an attack (Article 51), equally valid customary law permits a first use of force if the danger posed is "instant, overwhelming, leaving no choice of means and no moment for deliberation." Drawn from an 1837 event known as the Caroline Incident, which concerned the unsuccessful rebellion in Upper Canada against British rule, this doctrine builds upon the 17th-century classic formulation of Dutch scholar Hugo Grotius: Self-defense, says "The Law of War and Peace" (1625), may be permitted "not only after an attack has already been suffered, but also in advance, where the deed may be anticipated." Later, in his classic text of 1758, "The Right of Self-Protection and the Effects of the Sovereignty and Independence of Nations," Swiss jurist Emmerich de Vattel affirms: "A nation has the right to resist the injury another seeks to inflict upon it, and to use force and every other just means of resistance against the aggressor." In short, Article 51 of the U.N. Charter limiting self-defense to circumstances following an attack does not override the customary right of anticipatory self-defense. Interestingly enough, the works of Grotius and Vattel were favorite readings of Thomas Jefferson, who relied very heavily upon them for crafting the Declaration of Independence.
Now, if we look very literally at the Caroline case, we note an implicit distinction between preventive war (which is never legal) and pre-emptive war. The latter, it seems, is not permitted merely to protect oneself against an emerging threat, but only where the danger posed is "instant" and "overwhelming." Using such a literal framework, it would appear doubtful that the United States could construct a compelling argument for pre-emption against Iran under international law. This would be the case even if the American operation were limited meticulously and precisely to incontestably nuclear targets.
However, we no longer live in the 17th or 18th or 19th centuries, and the risks posed by a nuclear Iran could never possibly have been anticipated by Grotius, Vattel or later jurists focused on the Caroline case. Indeed, the permissibility of anticipatory self-defense is much greater in the nuclear age, where waiting passively to absorb an enemy nuclear attack before striking defensively oneself could be suicidal. In addition, there is the special danger posed by terrorist group surrogates. If not prevented from receiving nuclear weapons from patron states, such surrogates could inflict terrible harm upon countries out of the range of nuclear-tipped ballistic missiles.
The United States is not the only country at risk from Iranian nuclear weapons. Israel is at vastly greater risk. Yet, there is a long and venerated legal tradition that great powers have special responsibilities, and it is likely that today we are the only great power which has any operational chance of accomplishing this difficult mission. To be sure, in the best of circumstances, an expression of anticipatory self-defense against Iran would be broadly multilateral and fully endorsed by the United Nations. Sadly, we don't yet live in the best of all possible worlds, and the only viable alternative to an American defensive strike against Iran may be an unimaginable nuclear nightmare.
International law is not a suicide pact. There can never be any stable balance of terror in the Middle East. Functioning under certain Islamic leadership elites, Iran could conceivably consider using its nuclear weapons against "infidels" despite the reasoned expectation of massive nuclear retaliations. In such cases, deterrence would be immobilized and Iran could even become a suicide-bomber writ large -- a state willing to "die" to achieve certain presumed religious obligations.
Let President Bush take heed.
Louis Rene Beres is the author of several books and articles on international law.