Bashar is a happy man today. Long did America and the EU rub their hands with delight each time a minister or general left Assad to collaborate with the regime’s enemies.

Every split within the Assad government was paraded as the “tipping point”. And now, suddenly, what Assad’s lads had been telling us for months – that it is their enemies who are divided – turns out to be true. The bodies of Kamal Hamami and his brother are the proof. The rebels are split. The Islamists and the Free Syrian Army are at war.

The Obamas and the Camerons are going to have to catch their breath. They, after all, want – or wanted – to send weapons to the FSA, the secular, “heroic” resistance fighting for “democracy” against the fascist regime of the dictator in Damascus. And our leaders can still make the argument that the FSA are the guys we should be arming, now that the al-Qa’ida outfits have started killing the FSA leadership. If the good guys in the FSA are now fighting the bad guys of the Islamic State of Iraq and the Levant, we should help them.

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But history suggests that the good guys might turn into the bad guys and that the bad guys might win. What if the Islamists wipe out the FSA? Then our weapons really will fall into the “wrong hands” rather faster than they would have done anyway – since guns are money in civil wars and al-Nusra and the rest have the cash to buy anything we give the FSA. Then there’s the argument that does not occur to the Hagues and Kerrys of this world: that if the FSA really do want to polish off their former fundamentalist allies, then their obvious ally is the chap in the presidential palace in Damascus.

Bashar would be only too ready, surely, to help the FSA against the regime’s Islamist “terrorist” antagonists – and maybe offer the FSA a dignified reunification with the government army. Regime intelligence officers have for more than a year held regular meetings with FSA officers to try and woo them back to Bashar. And if they are successful, then our generous donations of weapons will end up not in the Islamist “wrong hands” but the “wrong hands” of the Baath Party.

But why be surprised at all this? Rebels almost always fall out. Anti-Russian Shia and Sunni resistance movements in Afghanistan fought each other when the Soviets still occupied their country – and then went on to kill each other in a civil war which allowed the Taliban to take over Afghanistan. In Algeria, the FLN destroyed the rival MNA – a nationalist movement which may also have been French-paid – before driving France out of its North African colony in 1962. And the Second World War provides far more examples of heroic maquisards killing heroic maquisards.

In Yugoslavia, the British dropped arms to Mihailovic’s monarchists in their struggle against Nazi occupation – until the British SOE told Churchill that Tito’s Communists were killing more Germans than Mihailovic’s men. When Churchill then switched sides to Tito, a young SOE officer asked the Prime Minister if he realised Yugoslavia would become Communist after the war. Churchill shot back: “Do you intend to live in Yugoslavia after the war?”

You bet Obama and Kerry and Cameron and Hague do not intend to live in Syria after the war. But it might be a good idea if they thought through who might actually win before they send weapons to their friends in the FSA.