SEOUL – North Korea’s Kim Jong Un declaring he will never give up his nukes and enshrining a “first-strike” doctrine into law are part of a worrying new escalatory dynamic in nuclear weapons policy around the world, analysts say.

Since the height of the Cold War, nuclear arsenals have served primarily as a deterrent to be used only as a last resort.

But when Russia invaded Ukraine in February, everything began to change, experts say.

Russian officials have refused to rule out the possibility of a nuclear strike against Ukraine, and President Vladimir Putin has repeatedly made thinly veiled threats of nuclear war.

On Wednesday, he vowed that Moscow would use “all the means at our disposal to protect Russia”.

North Korea – long a global pariah for its nuclear weapons programme – revised its laws this month.

It declared itself to be an “irreversible” nuclear power and offered an array of scenarios when it would use its nukes.

“We have entered a new era in which one nation is open to using nuclear weapons, in contrast to the Cold War doctrine,” Kim Jong-dae of the Yonsei Institute for North Korean Studies told AFP.

With talk of “automatic” first strikes and tactical nuke deployments, North Korea’s new policy “reflects Kim’s response to changing nuclear dynamics around the world”, he said.

It is not just Putin that Pyongyang is responding to: the United States has also played a role, the analyst added, pointing to the revival of its tactical nukes – smaller weapons designed for battlefield use – under former president Donald Trump.

The Pentagon under Trump had pointed in 2018 to Russia’s tactical nukes to make the case for the United States to have matching weapons as a credible deterrent.

“We should not equate Pyongyang’s latest move as an irrational decision or Kim being unpredictable. Kim is being nimble in adapting to a new global trend,” he said.