It’s the overwhelming power of America’s army. We are one of the top military’s in the world.
You should study the wars we’ve been in to learn more about this. You can also go to military websites. Maybe even other military’s to see how we stack up. You should investigate our topic by looking up ‘Nukes‘ on your preferred search engine. You will find a wealth of information.
We made nuclear reactors with the same technology. They use nuclear fission or fusion with Uranium or Plutonium to create an explosion that levels whole cities and burns people to the point where they became nothing but shadows on the wall.