More servicemen died during the last year of the Carter presidency than during any year of the Bush presidency. (I don’t think the last year was an aberration, but I don’t have the data available for 1977-79.)
What those deaths accomplished was the removal of two dictatorships. Some of the violence since the removal of Saddam and the Taliban has been due to Iranian agents, who would be less of a problem if the Iranian regime had been confronted earlier, by any of W, Clinton, HW Bush, Reagan, or, yes, Carter.