Trump and Biden have issued pardons at a faster clip than their predecessors. Many of their decisions appear to have been political or personal in nature.
The agency's budget has grown steadily since the 1960s, fueling an industry that creates lifesaving medicines and attracts billions of dollars in investment.
Just war theory, a centuries-old field of ethics, deals with how and when to start conflicts. It can also guide decisions about how and when to end them.