Rolf Mowatt-Larssen, a former CIA Moscow station chief, warned that it would be "terribly irresponsible" of Western leaders to ignore Putin's threats of nuclear warfare.

Michael Morell, host of the CBS show "Intelligence Matters" and a former acting director of the CIA, asked Mowatt-Larssen if he thought Putin's threats to use tactical nuclear weapons were a real threat.

If any Western leader thought of these threats as being bluster or saber-rattling, it would be terribly irresponsible.

He believes that the Western leadership is taking the threats very seriously.

According to Mowatt-Larssen, there was no reason for Putin to use nuclear weapons.

He said that he couldn't use tactical nuclear weapons on the battlefield to win a war. Nuclear weapons are not capable of taking territories. They do not have territories. It's a way to hit back at an enemy with an asymmetric weapon. The danger is that.

As the Russian army weakens and the Ukrainians get stronger, the risk of Putin using nuclear weapons is going to increase.

Mowatt-Larssen thinks that Putin will be advantaged if he uses the weapons.

Mowatt-Larssen said that doing so would be an act of capitulation forUkraine and its leader Volodymyr Zelenskyy.

He doesn't want to do that. They were too aggressive. He said that Zelenskyy had lost a lot. He is likely to intensify the battle on the ground in order to defy Putin. If that succeeds, it puts Vladimir Putin in a bad position because his options are also going to dwindle.

Around 15% of Ukrainian territory has been annexed by Putin. There were sham referendums in the four occupied regions.

Experts have voiced fears that Putin could use nuclear weapons in Ukraine and have interpreted Putin's annexation of these regions as a sign that Russia is determined to escalate the conflict.

William Burns, the director of the CIA, said it was hard to tell if Putin was bluffing.

In an interview with CBS that aired on Sunday, Burns said there was no evidence of an imminent threat of using nuclear weapons.