Saturday’s strikes on Iranian terrorist infrastructure have predictably revived the familiar debate about “preemptive” self-defense under international law. But the debate often misses the practical, fact-bound question: was the United States responding to a speculative future risk, or to an ongoing campaign of hostile action that has already crossed the threshold? On the public record, Iran’s hostility looks less like rhetoric and more like sustained operations.
This distinction matters. In strategic theory, there is a difference between initiating violence and terminating a pattern of violence, between starting and ending a conflict. Iran’s campaign against U.S. military forces and interests did not begin this week. It has spanned decades. The relevant legal and strategic question is not whether Tehran might one day act. It is whether a pattern of armed attacks, proxy operations, missile strikes, and assassination attempts already constitutes an ongoing armed attack under Article 51 of the U.N. Charter.
Article 51 preserves the “inherent right of individual or collective self-defense if an armed attack occurs.” Some read that as a strict sequencing rule, but state practice treats it differently. Where a state faces a continuing pattern of force, or repeated, closely linked strikes, it may treat the series as meeting the “armed attack” threshold and act to prevent further attacks, so long as its response is necessary and proportionate.
The hard limits are factual, not semantic: What is the threat? Is it ongoing or imminent? What alternatives exist? And is the response calibrated to prevention rather than punishment? Once that line is crossed, lawful self-defense can aim not only to repel the last attack, but to stop the next one.
Iran’s record is not ambiguous.
Since the Islamic Revolution, Iran has fueled attacks through Hezbollah, Hamas, and the Houthis, killing hundreds of American servicemembers — 603 in Iraq alone, according to a 2019 Pentagon report. On January 8, 2020, Iran launched a ballistic-missile strike on Al-Asad Air Base and Erbil, injuring more than 100 U.S. troops. Between October 2023 and February 2024, Iran-backed forces conducted over 170 attacks on American bases in Iraq, Syria, and Jordan, killing and injuring Americans. Additional rocket attacks followed. Authorities in the United States have reportedly disrupted multiple Iranian assassination plots targeting American officials.
This is not conjecture; it is a documented operational pattern.
Alongside kinetic attacks, Iran’s cyber campaign reflects the same logic of persistent pressure. American authorities have attributed or linked Iran-connected actors to operations targeting American institutions and infrastructure, including denial-of-service attacks on banks, attempted hospital intrusions, and infrastructure targeting. Cyber operations do not always meet the legal threshold of “armed attack,” but they form part of an integrated coercive strategy: normalize aggression below the threshold, blur attribution through proxies, and test the limits of American restraint.
Nor did that pattern end after the June 2025 confrontation. American interests remained in the crosshairs. Rocket attacks were foiled. U.S.-funded infrastructure was struck. Militia networks continued to operate within Iran’s broader apparatus of support and enablement. Whether carried out directly or through proxy layers, the operational reality was unchanged: American personnel and interests remain targets.
That is why calling this attack “preemption” obscures more than it clarifies.
On the domestic side, the constitutional picture is equally clear. Under Article II, presidents have the authority to repel attacks and protect American forces and interests abroad. The War Powers Resolution even presupposes that authority by requiring reporting after hostilities begin. It does not require advance permission to defend Americans under attack, and there is longstanding bipartisan recognition that the commander-in-chief may act swiftly in defense of U.S. personnel and national security interests.
As it relates to urgency and imminence, according to officials, in the hours leading up to the operation, the United States had indicators that Tehran was going to launch a strike against American assets in the region. The President decided to prevent those launches from occurring. The law does not require the commander-in-chief to wait until American lives are lost to prove a point about process.
Critics argue that decisive responses are destabilizing. But instability does not originate in the act of defense. It originates in sustained aggression.
The present debate has also mischaracterized the stated objectives of the mission. The president did not frame this as a project of political transformation. In fact, he articulated defined security objectives: ending Iran’s pursuit of nuclear weapons, halting expansion of its ballistic missile arsenal, preventing development of longer-range missile systems capable of reaching the United States, neutralizing threats to close the Strait of Hormuz, and degrading networks responsible for killing Americans. The purpose of limited, calibrated strikes is not regime change for its own sake. It is to degrade capability, restore deterrence, and reduce the probability of future attacks. Regime change, if it occurs, is a byproduct. The strategic objective is threat elimination tied directly to the national security interests of the United States.
Those interests are concrete. Iran’s nuclear trajectory threatens to convert a chronic threat into an acute one. A nuclear-armed Tehran would constrain America’s freedom of action, embolden proxy networks under a nuclear umbrella, and accelerate proliferation across the Middle East. It would place U.S. military forces in Qatar, Bahrain, Iraq, and elsewhere under greater strategic risk. It would increase the chance that a miscalculation becomes a catastrophe.
Iran’s ballistic missile expansion compounds that risk. Its medium-range missile arsenal already threatens regional allies and American forces. Its pursuit of longer-range systems raises the specter of expanded reach into Europe and beyond. Combined with repeated threats to disrupt the Strait of Hormuz — a globally vital economic chokepoint — these capabilities directly implicate American economic and security interests.
Deterrence is not about punishment. It is about prevention. It seeks to convince an adversary that aggression will not pay. Against a regime that finances terrorism, threatens leaders, probes infrastructure, and openly declares hostility, restraint without consequence invites repetition.
Iran’s proxy model deliberately manufactures legal and ethical confusion. Attacks are launched from dense civilian environments. Responsibility is diffused. Blame is inverted. International humanitarian law does not excuse that tactic; it condemns it. The legal standard under Article 51 is necessity and proportionality, not passivity. International law was never intended to require a state to absorb attacks while debating terminology.
Peace is not sustained by wishful thinking. It is sustained by credible lines and credible consequences. “Peace through strength” is not rhetorical flourish. It reflects a long-standing deterrence principle: aggression declines when it becomes predictably costly.
In the end, the choice is not between war and peace in the abstract. It is between allowing a sustained campaign of violence to continue or lawfully acting to prevent its next phase. When a regime finances terrorism, launches missiles, supports attacks on American troops, attempts assassinations, and advances capabilities that magnify those threats, the right of self-defense is not theoretical.
Article 51 is not a suicide pact. It exists for precisely these circumstances.
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Mark Goldfeder is an international lawyer, CEO of the National Jewish Advocacy Center and a law professor at Touro Law School.
John Spencer is Chair of War Studies at the Madison Policy Forum and Executive Director of the Urban Warfare Institute. He served 25 years as an infantry soldier, including two combat tours in Iraq. He is author of the book Connected Soldiers: Life, Leadership, and Social Connections in Modern War and coauthor of Understanding Urban Warfare.
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