Led by a top general vowing to “restore democracy,” armored vehicles rammed the doors of Bolivia’s government palace Wednesday in what the president called a coup attempt, then quickly retreated — the latest crisis in the South American country facing a political battle and an economic crisis.

Within hours, the nation of 12 million people saw a rapidly moving scenario in which the troops seemed to take control of the government of President Luis Arce. He vowed to stand firm and…