After more than four hours of talks in California, Xi Jinping and Joe Biden appear to have reached an understanding to stabilize ties between their nations. The Chinese and US presidents agreed to restore high-level military communications, jointly combat the fentanyl trade, and launch a dialogue aimed at preventing artificial intelligence from threatening global security.

Any number of factors could derail that fragile rapprochement, from Taiwan’s upcoming elections to an inadvertent clash in the South China Sea. Still, the fact that the two leaders appear to have rekindled the personal rapport they established in their last meeting, one year ago in Bali, is a welcome development.