US-China conundrum: Can hotline diplomacy work if trust isn’t a goal?

How do you preserve crisis communications with an adversary who is suspicious of your use of them? The U.S. is finding China isn’t interested in hotlines, which spells trouble as their rivalry heats up.

Shortly after the U.S. Air Force shot down a Chinese balloon that had traversed the continental United States for several days last month, Defense Secretary Lloyd Austin placed a call to his counterpart in Beijing.

At his disposal: a special hotline intended to help the two increasingly competitive global powers to prevent sudden tensions from deteriorating...