Since taking office, South Korean President Yoon Suk-yeol has anchored his strategy for countering North Korea on the U.S.-ROK alliance. American bombers have joined shows of force after DPRK missile tests. Seoul has ramped up military cooperation with Tokyo at Washington’s encouragement. And the allies have increased coordination on U.S. nuclear planning, repeatedly threatening to “end the regime” if Kim Jong Un uses nuclear weapons.

“I have complete faith in America’s ironclad commitment to extended deterrence,” Yoon said during a visit to the Pentagon last year.

Now, the return of