Nuclear weapons
Mass destruction
different types of weapons
They require distinguishing between civilians and soldiers, and prohibit indiscriminate methods of attack that are not directed at a specific military target.
Types of nuclear weapons include atom bombs, hydrogen bombs, fission bombs, and fusion bombs.
The reasoning is that since the threat or use of nuclear weapons violates international treaties that the United States has signed and ratified (e.g., the Geneva Convention), then the threat or use of these weapons should be illegal.