North Korea has arrived as a nuclear power, and there is no going back. Once the reality-show theatrics of the Singapore summit meeting subside, we are left with the reality that North Korea was just recognized as a de facto nuclear weapons power.

President Trump went to the meeting with Kim Jong-un of North Korea to try to take the keys to Mr. Kim’s nuclear kingdom. Whatever the terms of the statement released at the end of the meeting, Mr. Kim has not committed to anything concrete. He is not surrendering North Korea’s nuclear weapons and has walked away the big winner.

North Korea declared its nuclear weapons force technologically complete at the end of 2017, with its third successful test of an intercontinental ballistic missile. Now, less than a year later, North Korea’s nuclear power is politically complete, thanks to the legitimacy that comes from a handshake with an American president. Mr. Kim did what neither his father nor grandfather could do before him: sit down and negotiate with a president of the United States. The Singapore summit meeting looks indistinguishable from a meeting between the leaders of two states with normal diplomatic relations. But this is far from where Washington and Pyongyang have ever stood. It was Mr. Kim’s development of nuclear weapons — and the credible means to deliver them to America — that made the meeting possible.

Didn’t he just agree to “work towards complete denuclearization of the Korean Peninsula”? He did. Just like his grandfather’s deputies did in 1993. That phrase — “denuclearization of the Korean Peninsula” — is a term of art that the United States and North Korea can interpret to suit their interests.