A generation has passed since the peak in AIDS-related deaths. Few people under 30 years old understand what AIDS does to the body. The U.S.-led global response to HIV has been so effective that AIDS wards of people wasting away are a vision of the past. Now health experts, patients and others fear those days could return if the Trump administration doesn’t reverse its abrupt freeze on foreign aid or no other global power steps into the void, and fast. The U.N. AIDS agency says there could be over 6 million AIDS deaths in the next five years.