Nuclear button

The "nuclear button" is a figurative term referring to the power to use nuclear weapons. "Pushing the nuclear button" refers to actually using them. The actual procedure for using such weapons is more complex than simply pushing a button. The "nuclear button" may be transferred to another official due to political changes or the incapacitation of a person currently in control of it.

Various nuclear countries have nuclear briefcases that accompany the leader (such as the president of the United States) allowing him or her to launch nuclear missiles at any time.

Depictions of a nuclear buttons sometimes appear in popular culture, an example being the music video for It's a Mistake in which an officer accidentally presses the nuclear button.

North Korean announcement
On January 1, 2018, Kim Jong Un announced during his New Year speech "the nuclear button is always on the desk of my office" in order to make the United States aware that he is able to attack the country at will. US President Trump responded via Twitter on the following day:

Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works! 2 Jan 2018