Well, the B-36 had its time as a peacemaker, but it didn’t last long as the main airplane for carrying nuclear weapons for the Strategic Air Command. It was the very first bomber that could carry nuclear weapons, and it could fly super long distances without needing to refuel.
But in 1959, it was time for it to retire, and a new plane called the Boeing B-52 Stratofortress took its place. So, even though it had an important role in the past, the B-36 was replaced by a newer and fancier plane. It’s like when your old toy gets replaced by a new and better one, but in this case, it was about important stuff like keeping the peace.