In a world where nuclear weapons could soon be in the hands of a rogue nation like Iran, an Israeli preemptive strike on Iran’s nuclear facilities would be fully justified. Despite its ban on aggressive war, Article 51 of the United Nations Charter clearly recognizes a state’s inherent right of self-defense against another state.
Thus, Israel has full authority to act unilaterally or collectively in its self-defense.
Yet, Article 51 does not create the right to self-defense; it is an inherent right of all states under customary international law. Further, determining when self-defense is appropriate lies, as it always has, with each state. Under the Charter, however, the UN Security Council is charged with responsibility to lift the burden of individual national self-defense and take appropriate steps to restore international peace and security.
Having said that, one must recognize that the muscular Security Council originally envisioned in the UN Charter has never materialized. As such, threatened states are almost always required to make their own decisions and bear their own burdens when threatened.
Article 51 allows Israel to use aggressive force against Iran’s nuclear program if an “armed attack” occurs. The plain language of Article 51 is satisfied when one state has used armed force to attack another state.
Under customary international law, an armed response is also permitted when an armed attack is imminent, thus allowing for a preemptive strike.
As such, an attack by Israel against Iran’s nuclear facilities would be legitimate for two reasons. First, Iran is already conducting armed attacks under the plain meaning of Article 51, through surrogates, Hizbullah, the Palestinian Islamic Jihad, and Hamas.
Second, even if one questions whether an actual armed attack has occurred (by discounting Iran’s use of surrogates), Israel is still justified in executing a preemptive strike because Iran’s actions constitute an imminent, existential threat to the State of Israel.
While no formal declared war exists between Israel and Iran, Iran’s actions already constitute an Article 51 armed attack against Israel. Iran has done so by providing financial, material, training, and personnel support to its terrorist surrogates—Hezbollah, Palestinian Islamic Jihad, and Hamas—in their continuing conflict with Israel. Thus, Iran has already executed armed attacks against Israel and continues to do so. As such, a de facto state of war exists between Israel and Iran. A strike by Israel against Iran is, therefore, a justified use of self-defense under the plain meaning of Article 51.
Regardless of Iran’s actions against Israel through its terrorist surrogates, Iran’s ongoing development of a nuclear program constitutes an imminent threat to Israel’s security that permits Israel to execute a preemptive strike in self-defense. Preemption has a long pedigree in western legal theory.
Under customary international law, the “armed attack” requirement in Article 51 that evokes a right of self-defense can occur when a state perceives that an “act of illegal aggression is immediately impending and inevitable.” Thus, rather than waiting for an actual attack, a state may execute a preemptive strike on the hostile state.
Historically, two elements must be met to legitimize a preemptive strike. The preemptive strike must be proportional and necessary. The necessity element is the usual focal point of any argument concerning preemption. In order to meet necessity, the acting state must have exhausted all other alternatives of dealing with the problem, and the threat from the hostile state must be imminent.
Regarding an Israeli strike against Iran’s nuclear facilities, the issue of imminence related to necessity will be—as it is in almost every case—the most contested issue in deciding the strike’s legality.
The traditional definition for when an attack is imminent is when there is “some outward act that initiates the attempt to harm such that the actual harm is close at hand.” Historically, an attack was considered imminent when a state could see the mobilization of enemy armed forces preparing for attack. However, the modern trend in international legal thought is that for an attack to be imminent, the threatened attack must be perceived as “instant, overwhelming, leaving no choice of means, and no moment for deliberation.” The hostile state must be about to launch an attack and not merely in the “preparatory stages of such an attack.”
Yet, even the more “modern” definition of “imminent attack” has lagged behind the development of technology, particularly the development of nuclear armaments and their rapid means of delivery. Under the historic definition, Israel would likely be required to wait until nuclear warheads were attached to missiles and were about to be launched. Yet, at such a point, there would be no chance for alternatives or room for deliberation. Failure to stop Iran before it reaches such a point invites disaster, because of the potential destruction from such an attack and the danger of waiting until it is too late.
One must note that the “concept of an immediate or imminent threat of attack reveals itself as a flexible one. It allows a State to take anticipatory action when there is a persuasive evidence of the existence of a probable, or in exceptional circumstances, even a potential threat of attack within the foreseeable future.” The definition of “imminent attack” must be adaptable to modern warfare, since the traditional definition of imminent attack fails to account for the lethality and danger of nuclear weapons.
If Israel deems that Iran is actively preparing for a nuclear attack against the State of Israel (an opinion amply supported by Iran’s continuous bellicose threats) and that failure to act would put Israel in grave danger of being unable to prevent that attack, the threat against Israel would be, in fact, imminent. As such, Israel would be justified in making a preemptive strike against Iran’s nuclear facilities so long as the attack were proportional and Israel had exhausted all other meaningful alternatives.
While the general rule in international law is that a state may not initiate aggressive war towards another state, an Israeli attack on Iranian nuclear facilities would not qualify as aggressive war; instead, it would simply reflect Israel’s inherent right to self-defense. Iran has engaged in actual, ongoing armed attacks against Israel for years through its Islamist surrogates. Hence, armed conflict between the two nations already exists.
However, even irrespective of Iran’s actions against Israel through its surrogates, a preemptive strike by Israel would be fully legitimate once Israel has determined that Iran’s nuclear program constitutes an imminent threat to Israel and its security, something that only Israel can do for itself.
This article written by Jay Sekulow and co-authored by ACLJ Senior Counsel Robert Ash is crossposted on Israel National News.