U.S. President Donald Trump tweeted Tuesday in response to North Korean Leader Kim Jong Un that his nuclear button is “bigger” and “more powerful” than Kim’s.

In reality, there is no nuclear button.

Each nuclear-armed country has its own system for initiating a nuclear strike, however, most depend on the government’s leader to confirm his or her identity before authorizing an attack.

In the U.S., launching a U.S. nuclear attack is a secretive and elaborate process that involves the use of a nuclear “football,” a 45-pound briefcase that is carried by a rotating group of military officers who accompany the president wherever he goes. The briefcase is equipped with communications devices and a manual that includes war plans. The manual has a list of locations that can be targeted by the U.S. military’s 900 nuclear weapons.

Should Trump order a nuclear attack, he would identify himself to military officials with codes, which are recorded on a card, nicknamed the “biscuit,” that is carried by the president at all times. The president would transmit the attack order to the Pentagon just outside Washington and to the Strategic Command in the midwestern state of Nebraska.

The president does not require an approval from anyone else, including Congress and the armed forces, to authorize a nuclear attack.[xyz-ihs snippet=”adsense-body-ad”]The war of words over nuclear buttons began Monday, when Kim said in a speech, “It’s not a mere threat but a reality that I have a nuclear button on the desk in my office.” He added, “All of the mainland United States is within the range of our nuclear strike.”

North Korea is an isolated country whose nuclear program was developed in secrecy and many international nuclear experts doubt there really is a button on Kim’s desk.

Although nuclear buttons are largely the figments of people’s imaginations, Trump responded to Kim by bragging on Twitter Tuesday his button was bigger.

“North Korean Leader Kim Jong Un just stated that the “Nuclear Button is on his desk at all times.” 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 and more powerful one than his, and my button works!”

How is a Nuclear Strike Authorized?

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