A just and lawful military action

Though Machiavelli is often credited as the father of political realism, it was Thucydides, writing in his History of the Peloponnesian War, who offered the most succinct summary of the concept. Among the nations, he explained, “the strong do what they can and the weak suffer what they must.”

A popular critique of President Trump and Israeli Prime Minister Benjamin Netanyahu is that their action against Iran is nothing more than a manifestation of this reality, that the strong have picked a fight because they wanted one, and the weak and isolated Iranians are made to suffer from the bullies’ aggression. That sentiment was reinforced on Wednesday as four libertarian-leaning Republicans joined all 207 Democrats in the U.S. House of Representatives to support a War Powers resolution to end the U.S. action, effectively a rebuke of Trump’s decisions.

A recent memorandum from the legal adviser at the U.S. Department of State effectively refutes these critics by thoughtfully situating the U.S. and Israeli joint action within the context of customary international law. Because concepts of “jus ad bellum”—whether a nation has a legal right to wage war—draw heavily from the just war theories at the heart of a Christian theological approach to the same question, the State Department’s answer has special relevance for people of faith.

The Department’s basic answer is that the United States has been at war with Iran since 1979, and Iranian leaders started it when they invaded our embassy and turned our diplomats into hostages. The Iranians continued to wage war against us, directly or through their proxies, off-and-on since then: the Beirut bombing of the Marine barracks in 1983, the Khobar Towers bombing in 1996, and arming the anti-U.S. terrorists resisting the transition to a peaceful Iraq post-Saddam, which killed hundreds of American soldiers. In more recent years (since 2019), Iran-aligned militias have conducted scores of attacks on U.S. bases and personnel in Iraq. These attacks were also the legal basis for the U.S. drone strike that killed Iranian General Qasem Soleimani in January 2020. Thus, the United States has significant self-defense interests in deterring and destroying the Iranian capacity to launch continued attacks on our citizens and military (and, by extension, the president has significant powers as commander-in-chief to defend those interests).

International law also permits the United States to support Israel in exercising that nation’s right to self-defense against Iran. The ayatollahs have funded and facilitated decades of attacks on Israel and Israeli citizens, mostly through their support of Hamas, which have ramped up in recent years.

Furthermore, both the United States and Israel have an urgent interest in preventing the Iranian regime from acquiring a nuclear weapon, especially in light of Iran’s violent rhetoric promising how it would aggressively use such a device. The department thoughtfully points out that the usual just war analysis of “imminence,” the idea that you can strike an opposing nation first if it is imminently going to strike you, looks different in the context of nuclear weapons, where the stakes are so much higher and the warheads are developed in secret.

The memorandum is smart to rely heavily on previous statements from officials in the Obama and Biden administration. The department’s analysis quotes from President Obama’s legal adviser, who had said that a temporary pause in hostilities does not mean that an entirely new “jus ad bellum” justification is necessary prior to renewed self-defense actions. It also cites nine letters from the Biden State Department to the U.N. Security Council justifying particular strikes by the United States against Iranian proxies like the Houthi militias in Yemen.

The work of the president’s highly capable legal team demonstrates a solid domestic and international legal basis for the president’s actions. And as Christians and citizens, we can better understand both the legal and ethical justification for our nation’s actions in self-defense.