The first modern general, William T Sherman, described war:

War is cruelty. There is no use trying to reform it. The crueler it is, the sooner it will be over.

The first modern President, Harry Truman, demonstrated Sherman’s description, from Federalist:

On August 6, 1945, 30-year-old U.S. Air Force pilot Col. Paul W. Tibbets Jr. took to the sky in the Enola Gay, his Boeing B-29 Superfortress heavy bomber. His destination, the Japanese city of Hiroshima, was not an especially notable target. His payload, however, a single bomb nicknamed “Little Boy,” would change the course of history.[…]
A near-impossible decision faced President Harry S. Truman in the summer of 1945. To his credit, and to the salvation of millions, his fateful choice was the right one.

Needless to say, Harry’s two days of Hell, would be no match for what eighteen months of Japanese suicide attacks, a Soviet offensive and possible US poison gas attacks.  After all, War is Hell.