The collapse of talks between President Trump and North Korean leader Kim Jung Un in Hanoi means that Pyongyang’s nuclear program will continue — and so, too, will the still unresolved Korean War, now nearly 70 years old.

The war, which ended with a truce but not a peace treaty, is famously forgotten in the United States, but it is invoked as legal authority every time a president sends U.S. troops overseas without congressional authorization.

The war was the first large overseas U.S. conflict without a declaration of war, setting a precedent for the unilateral presidential power exercised today. The Korean War has helped to enable this century’s forever wars. A peace deal, which Trump has talked of reaching, would not undo this forgotten legacy, but renewed American attention to the Korean War should be an occasion to rethink the president’s war powers.