December 01, 2017 "Information Clearing House" - Responding to North Korea’s test of an intercontinental ballistic missile that could threaten the United States' mainland, Secretary of State Rex Tillerson said in a press release: “Diplomatic options remain viable and open, for now.”

At an emergency meeting of the U.N. Security Council on Wednesday, U.S. Ambassador Nikki Haley said while the U.S. does not seek war, “if war comes, make no mistake, the North Korean regime will be utterly destroyed.”  

But diplomacy is not just viable, as Tillerson says; it’s legally required by the Charter of the United Nations, which, as a treaty ratified by the United States, is the law of the land under the Constitution. This dimension of the North Korean crisis is not getting the attention it deserves.   

The charter prohibits the threat or use of force except when authorized by the U.N. Security Council or in self-defense against an armed attack. The Security Council is intensively addressing the crisis, including in Wednesday’s meeting, and it’s significant that it has not seen fit to authorize the use of force.  

Unless and until it does, the U.S. is bound by law to seek a diplomatic solution. Seeking a military one, in addition to its horrific humanitarian consequences, would violate the charter and put the U.S. on the wrong side of the law.

We’re currently operating under Resolution 2375 of September 11, 2017, which tightened sanctions on North Korea after it tested a powerful nuclear bomb. It was adopted pursuant to U.N. Charter Article 41, which covers measures not involving the use of force, such as economic sanctions.

Neither 2375 nor previous Security Council resolutions on North Korea contain any indication whatever that force is authorized. In fact, they emphasize the need for a peaceful settlement, which is also mandated by the charter.

Article 2(3) obligates all members to “settle their international disputes by peaceful means in such a manner that international peace and security, and justice, are not endangered.”

There is a reason Security Council resolutions on North Korea are written this way. China and Russia are implacably opposed to a military strike, and have the power to veto resolutions they oppose.

They learned their lesson in the run-up to the 2003 U.S. invasion of Iraq, when the United States interpreted ambiguous language in Security Council resolutions to authorize the invasion.

That interpretation was incorrect, but since then China, Russia and other members of the council have taken extreme care to prevent the U.S. from making similar maneuvers.

Those inclined to scoff at the idea that the U.N. or international law could restrain the U.S. from using its military might haven’t really understood the situation. This is not just a matter of international legalisms for policy wonks. The geopolitical stakes are real, and high.  

China might well intervene militarily if the United States started a war with North Korea. In negotiations on Resolution 2375, China and Russia supported including a provision forbidding military action north of the 38th parallel dividing South and North Korea.

That provision was refused by the U.S., but it shows how opposed Russia and China are to use of force in the region. Their position is backed by law, which, as permanent members of the Security Council, they shape by refusing any authorization of force.

Article 51 of the U.N. Charter does recognize “the inherent right of individual or collective self-defense if an armed attack occurs … until the Security Council has taken measures necessary to maintain international peace and security.”

But since the George W. Bush administration, U.S. doctrine has permitted preemptive attacks against serious threats, particularly weapons of mass destruction. While the term is usually avoided, this is essentially a doctrine allowing preventive war.

This August, Trump’s chief of staff, General H. R. McMaster, broke protocol and referred to a possible “preventive war” against North Korea.

That U.S. position is not backed by law. Preventive war is plainly illegal under the U.N. Charter, which permits military action as a matter of self-defense only in response to an actual armed attack. At most, military action might be allowed in response to the early stages of an attack.

Again, this is no wonkish, legalistic fine point of parsing the charter; it’s of vital practical importance. Preventive war proved profoundly destabilizing and destructive in the Middle East, and would again on the Korean Peninsula.

Amid Trump’s incendiary “fire and fury” rhetoric, Congress is also beginning to debate the legality of a conventional or nuclear strike against North Korea, and the limits of the president’s power to order one.  

At a November 14 hearing of the Senate Foreign Relations Committee, Brian McKeon, former committee lawyer and former Pentagon official, testified that the Constitution requires any war with North Korea to be authorized by Congress. Two bills were recently introduced in Congress requiring its specific approval of war with North Korea, and two others require Congressional approval of the first use of nuclear weapons or rule it out altogether.

Also at the Senate hearing, former Commander of Strategic Command Robert Kehler pointed out that the U.S. military is duty-bound to refuse a president’s order to use nuclear weapons if it’s illegal.

He testified that to be legal, use of nuclear weapons must comply with requirements of necessity, proportionality and discrimination under the international law of armed conflict.

What Kehler did not say is that given their uncontrollable and indiscriminate effects, an order to use nuclear weapons would fail those tests, and be illegal.

There was zero discussion at the hearing of the illegality of the U.S. attacking North Korea under the U.N. Charter.

Yet as we learned from the Iraq War, there is great wisdom in the charter requirement that peaceful solutions, however difficult to achieve, take precedence over resorting to force.