Yes, it is an ignorant thing to say that the United States of America will never be hit with a nuclear bomb.
Several enemy nations of the USA have nuclear bombs (China, Russia, North Korea, etc.), and they can use these nuclear bombs against the USA in wafare.
All weapons which are built are eventually used. This will be the case with nuclear bombs.
God is the only true shield. Unless the United States of America illegalizes homosexuality, God may allow America’s enemies to hit the USA successfully with a nuclear strike.
You can only trust God 100%!