Many Americans were aghast at President Trump’s announcement this month that he would meet with North Korean dictator Kim Jong Un.

But in moving toward diplomacy, Trump is following in the steps of previous presidents. If he continues down their path, the end result would be a deal that allows Pyongyang to keep its nuclear weapons — not because Trump gets taken in by Kim, but because such a deal boosts American interests. Since World War II, the United States has labored to prevent nuclear weapons from spreading. But once a country has them, Washington ultimately accommodates it, opting to develop some kind of diplomatic influence, if not control, over other nuclear powers, instead of going to war.