Beijing says that it will step up imports of US crude as part of a compromise deal hammered out in recent days that looks to have averted a trade war.

On the surface it’s a win-win: China would likely have imported more US crude in any case, and Trump can claim the resultant fall in his country’s trade deficit with China as a famous victory, even though the net effect on the country’s trade position will be near-zero (if the cargoes weren’t going to China they would...