None.
The U.S used no nuclear weapons whatsoever on Vietnam.
No it didn't.
Fear that the North Vietnamese would obtain nuclear weapons themselves (from Russia or China) and use them on South Vietnam or even on America.
Goldwater wanted to use nuclear weapons on Cuba and North Vietnam.
LBJ and General Westmoreland did discuss the use of nuclear weapons for use in the Vietnam War, but LBJ ultimately instructed his subordinates to drop the matter and not to bring up the issue of nukes again. This issue had also surfaced during the Korean War and General MacArthur got sacked for it (among other reasons). Note: Only Russia (USSR) & Red China on the communist side had atomic weapons during the Vietnam War. Vietnam never agreed not to hit the US with an atomic bomb because 1) Vietnam has never had any nuclear weapons of any type, 2) Vietnam has no delivery system to send such weapons outside its own border.
No, Nazi Germany had no nuclear weapons.
Most definitely. Simply had to invade North Vietnam. If the Soviets or Red China intervened; use nuclear weapons against them. Which is why North Vietnam wasn't invaded.
Although US agreed several arms agreements banning use of nuclear weapons, USA DOES use nuclear weapons and in fact, US is the ONLY nation to have used nuclear weapons in war.
No nuclear weapons have been used in Afghanistan to date.
Some of the countries have nuclear weapons because they use them as a defense mechanism. The nuclear weapons are intended to be used whenever there is a war.
the u.s. used non nuclear weapons and nuclear weapons against japan
They had nuclear missiles machine guns and cool guns