Why on earth would Russia back out on a sweet deal with John Kerry that had allowed it to cash in on its Syria gamble and become the United States' senior partner in shaping Syria's future and in the coalition for the war against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS)?
By trampling over the much-hyped US-Russia brokered ceasefire in Syria, Vladimir Putin has proved right Kerry's detractors in the Obama administration. Cynical as they may be, the Pentagon and the CIA have questioned Russia's seriousness about the ceasefire and the diplomatic process from the very beginning.
Russia has taken advantage of Kerry's concessions, not to exercise influence over Bashar al-Assad, but rather to unleash him to "retake the whole country" from the "terrorists".
US slams Russia over 'barbarism' in Syria
But if the US gamble on Russia has failed, Putin is now overplaying his hand and he too will fail, despite recent territorial gains. Does Moscow seriously believe it can benefit by going it alone, supporting a brutal regime in a bleeding nation?
The ill-conceived ceasefire hardly lasted a few days. It was broken by a spectacular attack on a UN aid convoy outside Aleppo on September 19.
In the following days, Putin and Assad subjected the city to some of the worst bombardment of the war. Hundreds more died.
The Russian military escalation has led to western diplomatic escalation. On Sunday, France and Britain joined the US in condemning Putin and Assad's "war crimes" in Syria at the UN Security Council.
The (misplaced) admiration for Putin's 'masterful' military intervention on the side of the Syrian dictatorship has given way to dismay and disgust in the region and beyond, as Russia tries to force a military solution on the fractured nation.
The (misplaced) admiration for Putin's "masterful" military intervention on the side of the Syrian dictatorship has given way to dismay and disgust in the region and beyond, as Russia tries to force a military solution on the fractured nation.
But spouting verbal condemnation of Putin/Assad violations in Syria amounts to issuing speeding tickets during a Formula One car race.
Predictably, Russia's UN ambassador Vitaly Churkin has doubled down at the Security Council, claiming that: "Bringing a peace is almost an impossible task now."
There's little doubt that Obama's failure to act in Syria has brought about Russia's intervention.
Obama claims that he is constantly "haunted" by the Syrian tragedy but remains adamant that there was nothing he could have done that could have produced a better outcome in Syria.
I disagree. For starters, he could have worked with Turkey and others to provide protection for civilians within safe zones in Syria, and mitigated the horrific flux of refugees into neighbouring countries and beyond.
He says with a certain humility, real or fake, that perhaps he should have thought harder and went about it differently: "… there are times where I think I wish I could have imagined a different level of insight."
US President Barack Obama [REUTERS]
Be that as it may, he did fail to act, no less when Assad trampled over his - and the international community's - red line by using chemical weapons against his own people. The result is clear to see: hundreds of thousands of deaths, millions of refugees, and a country destroyed.
But when Russia took advantage of the void and acted where the US failed, Obama saw a challenge and an opportunity. Russia became Assad's patron, and a potential co-sponsor of a diplomatic solution in the country. As the US engaged Iran on the nuclear issue, it engaged Russia on Syria.
Enter Kerry, the enthusiastic diplomat with grandiose pretensions. Certain of his ability to convince his counterpart Sergey Lavrov to play ball, he went on to make one concession after another, culminating in dreadful deals that anointed Putin peacemaker, rehabilitated Assad, weakened the opposition, and strengthened ISIL.
But when Russia exploited the US concessions to act even more aggressively in Syria, Kerry's threat of resorting to "plan B" failed utterly to deter them from acting with impunity.
John Kerry at a Security Council meeting about the situation in Syria [EPA]
Why? Well, because the administration had no "plan B", and Kerry had to play with the cards Obama dealt him.
So once again I ask why did Putin turn his back on a deal that would strengthen Assad, weaken the opposition, and partner Russia with the US to fight ISIL, paving the way for more compromises in Syria and potentially over Ukraine?
The short answer: Arrogance.
Ever since the Russian forces entered Syria on the side of the Assad last September, the tide of war has shifted in their favour. The Syrian regime, which was falling apart in the first half of 2015 despite assistance from his allies in Iran, Iraq and Lebanon, began to regain the initiative - all thanks to Russia.
Ever since the Russian forces entered Syria on the side of the Assad last September, the tide of war has shifted in their favour.
Suddenly, regional leaders flocked to Moscow to meet Putin, and western leaders sought his influence to end the war. Russia became co-sponsor of the Geneva "peace talks" and even dabbled with the idea of becoming a peace broker in Israel/Palestine.
But this could not go on open-endedly with Syria falling apart in the process and chaos spelling over to neighbouring countries.
Putin's gamble paid off, but he failed to cash in his chips. Like a gambler enjoying a winning streak, he reckons he could go on winning.
But what will he gain now, assuming he and his Syrian crony conquer Aleppo, aside from a horrific humanitarian disaster and a destroyed city?
What will he gain if he attained his maximalist goal of conquering the whole country, apart from a weak vengeful dictatorship ruling over a broken people, sowing more extremism?
In reality, there is no such thing as a military victory in Syria, not even in the distant future. If anything, Putin will once again face the very same Afghan syndrome he has been trying to overcome in Syria. A protracted war that will bleed Russia as it breaks Syria.
Arrogance breeds stupidity.
Marwan Bishara is the senior political analyst at Al Jazeera. Follow him on Facebook.