WASHINGTON (AP) — The U.S. military is waiting for clarity from the Pentagon following President Donald Trump’s back-and-forth on troop levels in Europe, upending the lives of military personnel and potentially costing taxpayers millions of dollars, two U.S. defense officials told The Associated Press. The Republican president announced on social media two weeks ago that he was sending troops to Poland — the same day the Pentagon had officially ordered the cancellation of a rotation of soldiers heading there, one of the defense officials said. The unit’s equipment was already on the way. Sending it cost the military $32 million, said U.S. Transportation Command, the military agency largely responsible for moving troops and gear across the globe. The abrupt changes are forcing the military to “retroactively engineer” a policy in line with the president’s latest pronouncement, the official said. Both officials were briefed on the decisions and, along with others, spoke on the condition of anonymity to discuss sensitive military matters. The uncertainty is not only rattling European allies worried about the message being sent …