Which of these sentences provides a strong conclusion for the fourth paragraph? Using the bomb established a lasting peace and proved that it was a good idea to develop a nuclear weapon. Truman was faced with a difficult choice in 1945, but he probably made the right decision. Truman refused to use a third bomb on Japan or to use the atomic bomb against Korea because he was horrified by its effects. Although there have been other wars since 1945, none have been as big as WWII or ended with as much devastation.