The past year saw a string of escalations on the Korean Peninsula as Pyongyang bared its nuclear and missile advances for the world to see. Then quite suddenly, the North’s hitherto posture of nuclear defiance was thrown into reverse at the Olympics. Now the outward signs of progress are piling up: the two Koreas are talking, a high-level summit on the border is planned for April, and South Korean officials have indicated that the North is willing to enter into talks on denuclearization.

These developments are clearly a step up from the brinkmanship of 2017. But they’re hardly a breakthrough given the history of U.S. diplomatic attempts to rein in North Korea’s nuclear program.