Since Israel commenced its campaign targeting the Iranian nuclear weapons and ballistic missile programmes, it has endured not only barrages of rockets, but also legal condemnation. Almost on que, Israel is accused of launching a supposedly unlawful war of aggression that cannot be justified by self-defence because the Iranian nuclear threat was not yet imminent. In reality, though, Israel is doubly justified striking these targets.
It is true that the international legal right for a state to use force in self-defence is triggered only by an actual or imminent unlawful armed attack. But once a war – what international law calls an armed conflict – begins, there is no need to make a self-defence assessment for every subsequent attack. In other words, during an ongoing armed conflict, the legality of attacks against the enemy is dictated by the international laws of war regulating the conduct of hostilities, not the law regulating resort to force in self-defence.
Israel and Iran have been engaged in an ongoing armed conflict for months if not years. Experts may disagree on when this armed conflict began, but Iran’s use of its proxies – Hezbollah, Hamas, and the Houthis – since at least October 7 is certainly a clear indication of unlawful Iranian aggression against Israel. And if that’s not good enough, then Iran’s barrage of missiles and drones launched in October 2024 certainly proves the two nations have been engaged in an armed conflict since then.
Wars do not progress on a flatline of intensity. Nor is a state victimized by unlawful aggression restricted in acting in its own territory to deter hostile actions. Indeed, history is replete with examples of the folly of assuming defensive shields provide impenetrable protection against an enemy. Just ask the French who endured four-plus years of Nazi occupation, or the IDF soldiers who were overwhelmed by Egyptians at the Bar-Lev line on Yom Kippur in 1973.
Defeating an enemy necessitates taking the war to him and attacking his most vital military capabilities. Yes, Israel’s missile defences are impressive. But we all now know something Israeli commanders almost certainly knew before this fight began: no shield is impenetrable.
This is why attacks on Iran’s most vital military assets – nuclear weapons production assets, its ballistic missile programme, air defences, command and control, and yes, even experts providing essential contribution to the development of a weapon that can kill millions of Israelis – are both operationally logical and legally justified.
But even if this campaign wasn’t part of an ongoing armed conflict and instead had to be assessed through the lens of state self-defence, Israel is equally justified. The existential threat Israel confronted was as grave as any state can face. And the indicators that Iran was truly on the verge of developing a nuclear weapon, coupled with the persistent, overt, and unqualified threats to “wipe Israel off the face of the earth” and in so doing “eradicate” a cancer to the world, rendered Israel’s imminence assessment reasonable.
As the distinguished international law scholar and practitioner Sir Daniel Bethlehem explained while serving as legal advisor to the UK Foreign and Commonwealth Office, assessing imminence involves consideration of a variety of factors, to include the gravity of the threat and whether the situation presents a last opportunity to avert that threat.
It might be appealing to lambast Israel for acting prematurely. But no other state would likely have tolerated the gravity of such a threat in the hands of a regime determined to kill millions of its people having already demonstrated a capability to penetrate the most sophisticated defensive shield. Demanding Israel forego the opportunity that presented itself to strike these targets – an opportunity created in part by the neutering of the proxy forces Iran had already been using to attack Israel – is in effect a demand that the Israeli people live under the proverbial Sword of Damocles.
Israel is not the aggressor here and was doubly justified in its decision to launch this campaign to rid itself of this unacceptable menace. Iran could have avoided this conflict by simply adhering to its nuclear non-proliferation obligations. It chose not to and has no one to blame other than its regime elites who inflicted this suffering on the Iranian and Israeli people. Echoing Iran’s victimhood narrative is not only perverse, but an incentive for those nefarious leaders to continue to stoke the flames of this conflict.
Geoffrey S. Corn is the George R. Killam, Jr. Chair of Criminal Law and Director of the Center for Military Law and Policy, Texas Tech University School of Law. He’s also a Distinguished Fellow, JINSA Gemunder Center for Defense & Strategy and a Member of the Center for Ethics and the Rule of Law Advisory Council.
