According to Leon Sigal, the director of the Northeast Asia Cooperative Security Project at the Social Science Research Council, Kim did that because he wants a fundamentally different relationship with the United States. During the Cold War, Pyongyang maintained good relations with both the Soviet Union and China, and played the two against each other to maximize its independence. Since then, the USSR’s demise has made North Korea overwhelmingly dependent on Beijing, its only significant ally. And Kim, Sigal argues, like his father and grandfather, doesn’t like that. He fears the United States. But he also wants a rapprochement with the United States—and through that, with America’s allies Japan and South Korea—because he believes his country will be stronger, and his regime more secure, if North Korea has more than one powerful friend.

The Singapore summit showed Kim that Trump is open to that. And by doing so in such a dramatic way, Trump makes it easier for Kim to push denuclearization at home. By getting the summit, Kim can tell his generals—who have labored for decades building the North’s nuclear program—that his strategy is working. Trump shook his hand.