Senior American officials increasingly believe the Chinese spy balloon shot down off the coast of South Carolina in early February was originally supposed to conduct surveillance over U.S. military bases in Guam and Hawaii, but that winds carried it off course to Alaska, Canada and finally the continental United States.

The evolution of Washington’s understanding of the Chinese military’s original goals and new details that reveal misreadings of the U.S. reaction by Chinese officials in private meetings reflect how difficult it is for the United States and China to discern each other’s intentions — a gap American officials fear could lead to greater mistrust in an already fraught relationship, or even to armed conflict.

In another example of the fog created by superpower rivalry and political imperatives, U.S. officials said in interviews Wednesday that they now increasingly believe three unidentified flying objects shot down over North America were unlikely to be surveillance devices.