Although it was less than 24 hours before that Vladimir Putin had appeared on giant video screens in Moscow and announced the incorporation of Lyman into Russia, by Saturday evening the 2,500 Russian troops bottled up in the town had enough. After a few days of asking for permission to withdraw, they simply fled. Carefully directed Ukrainian artillery had been picking off the defensive positions one-by-one, until soldiers could no longer be found to hold critical points.

Russia's official announcement, that its troops "withdrew to more defensible positions", hides the reality of a broader collapse in morale. Scratch units are being thrown together and sent to the frontline where, lacking cohesion and critical equipment and supplies, they dissolve. Once this process begins it's almost impossible to stop. Individuals become concerned about their own survival, begin blaming their commanders, and lack the will or motivation to fight. Planned movements to the rear risk turning into a rout and orders turn into scraps of paper that float in the wind.

What makes Lyman significant is that there's evidence that Putin was personally involved in ordering his forces to stay and hold. Obsessed with the need to keep the Russian flag flying over the town's rail station, he'd refused requests from his generals to pull back. He has even, reportedly, acted like Hitler in the final days of World War II, deciding which positions should be held and insisting how specific units should be deployed. Putin has, quite evidently, lost control of the ability to shape the actions of his forces on the ground. This doesn't mean, however, that he's likely to accept he has lost the war. On the contrary, the risk of dangerous escalation are becoming more and more likely by the day.

Putin may well be a deluded man living in an imaginary world of his own creation, but he still possesses nuclear weapons and is ready to use them.

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This explains Putin's sudden rush incorporating the four Ukrainian provinces into Russia. As he began to have inklings of the coming collapse, instead of reaching out to begin negotiations the Russian President finally focused on what he wanted from the invasion.

In those early days the armoured drive towards Kyiv, coupled with assaults along the Black Sea, suggest Putin expected Volodymyr Zelenskyy's soldiers to rapidly collapse. When they didn't, he pulled back in the north but continued opportunistically pushing in the south. This exposed his stretched support lines and left his best forces isolated when the Ukrainians eventually launched their attacks. Rather than return to the table for talks, however, that seems to have been when Putin began to decide exactly what he wanted: his bottom line was he would offer peace in exchange for four provinces.

Luhansk, Donetsk, Zaporizhzhia, and Kherson were to be his prize and that's why he held his sham referenda - as a fabricated excuse legitimising his brutality. The problem with this today is that, in doing so, Putin has created a red line for himself. This is his demand - one from which he cannot now back down, and yet can't hold with conventional military forces.

Which brings us to the nuclear issue, using bombs to create a wasteland.

Despite the significant Ukrainian advances, the reality is that the majority of the annexed areas remain under Russian control. Putin's call-up of untrained reservists may be desperate, however it provides a massive resource of manpower that will, eventually, restore the front and bolster his positions. And although in his broadcast speech the Russian dictator did hint at the use of nuclear weapons, he did not specifically threaten their use. What he has succeeded in doing, however, is signalling very clearly to the West what he wants. Although this is considerably more than Zelenskyy wants to concede, it is a deal that other European countries might be prepared to consider trading in return for peace. This is exactly what Putin wants - to split the alliance ranged against him before internal opposition coalesces to pull the dictator from his throne.

The implied nuclear threat rapidly moves the war towards its end game.

He understands that this conflict can now, in essence, only end in one of four ways: victory is off the table. Putin is signalling he wants a land grab for peace, leaving open the possible prospect of negotiating the specifics of new borders. Zelenskyy is ruling this out, demanding the complete withdrawal of the Russians. He hopes that with every day as the conflict continues the third possible ending - a coup in Moscow - comes into prospect. If, however, this does not occur (and, although Putin is under pressure he still retains complete control of all the security apparatus) then the intense danger of the final option becomes more and more likely. Rather than risk defeat on the battlefield, Putin will deploy tactical nuclear weapons in an attempt to restore the strategic balance.

This is exactly why the smaller bombs were originally developed. NATO was afraid that the sheer mass of Soviet forces would allow its units to penetrate its defences and transiting to low-yield nuclear weapons was seen as a signal to Moscow that continued fighting risked further escalation. Now it seems Putin is using this threat in a similar way. Although he is the aggressor and his demands are completely divorced from any basis in fact, he is banking on the fact that he has the bomb and Kyiv does not.

Reasoning with an irrational dictator is never easy. Getting them to admit defeat, particularly when they still have nuclear weapons, is probably impossible.