What are Kim Jong-un and Trump's nuclear buttons really like?

"The entire United States is within range of our nuclear weapons and the nuclear button is on my desk at all times. That is a fact, not a threat,"Telegraphquoted North Korean leader Kim Jong-un as saying on January 1. However, the "nuclear button" is believed to be a symbol referring to North Korea's nuclear power, not an actual device.

Nuclear powers maintain a direct chain of command from the top brass to the troops on duty. A simple push of a button cannot convey all the complex data involved in a nuclear weapons situation, such as the target, the number of weapons to deploy, and the confirmation of orders from above.

In fact, to activate the nuclear arsenal, heads of state must use complex systems such as the US "nuclear briefcase". This is a black, aluminum, leather-wrapped suitcase, weighing about 20 kg, with no buttons inside as many people mistakenly believe. Instead, it contains instructions for using the emergency broadcast system, a notebook with attack options, a notebook with safe havens, and a presidential identity card.

When the US president wants to confirm a nuclear attack, he must use a card with an authentication code, codenamed "the biscuit", which is also an indispensable item for the commander in chief of the US armed forces. The US Secretary of Defense must then confirm the order, before passing it on to his subordinates and the nuclear forces.

The “nuclear button” is a figure of speech meant to simplify the process. It is possible that Kim Jong-un wanted to reveal a device similar to a nuclear suitcase, which he would use to command North Korea’s nuclear forces. However, Pyongyang has not released any images of leader Kim Jong-un’s “button,” leading analysts to question its existence.

Kim Jong-un's claim that he has a nuclear button appears to indicate that Pyongyang has completed the development of nuclear weapons and is ready to put them into service. "This year we should focus on mass-producing nuclear warheads and ballistic missiles for combat deployment. These weapons will only be used if our security is threatened," Kim added.

"Someone please tell him that I too have a Nuclear Button, but it is a much bigger & more powerful one. And my Nuclear Button works," US President Donald Trump responded on Twitter. This is understood to mean that Washington has a much larger nuclear arsenal ready for combat than Pyongyang. The US military is currently fielding 6,800 nuclear warheads of various types, deployed on bombers, land-based intercontinental ballistic missiles (ICBMs) and submarines.

Meanwhile, North Korea is believed to possess 10-15 nuclear warheads, along with many types of ballistic missiles from medium to intercontinental range. The country has not yet demonstrated the ability to develop re-entry warheads equipped with complex guidance systems, the most important requirements for ICBMs. However, experts say Pyongyang is fully capable of mastering this technology in a short time.

After his nuclear button announcement, the North Korean leader also appeared to soften his stance in his New Year’s speech, mentioning the possibility of sending a delegation to the 2018 Winter Olympics, taking place in Pyeongchang, South Korea. This seemed to indicate that Kim Jong-un wanted to focus on the deterrent effect of nuclear weapons, rather than using them and starting a second Korean War.

"Showing off the nuclear button on his desk seems to be intended to intimidate President Trump, who once called the North Korean leader "little rocket man," wrote James Rothwell ofTelegraphcomment