AS THE Syrian ceasefire arranged by the United States and Russia teeters on the brink of collapse, it's clear the main problem lies in Washington.
Moscow's goal has never been in doubt: it wants the regime of Bashar al-Assad to survive. The Obama administration has been reluctantly moving towards the same conclusion but it simply can't admit it, even to itself.
The Russian government bitterly condemned the American air strike that killed 60 to 80 Syrian army personnel on Saturday, but everybody knows that air strikes sometimes hit the wrong people. It was a mistake, that's all, and the Russians really understand that -- but it was a mistake that tells us a lot about how far the US has moved.
Until recently the US, still formally pledged to overthrow the Assad regime, would not attack Islamic State troops if they were fighting the Syrian army. (That's why Islamic State captured the historic city of Palmyra two years ago: the US air force would not strike the long and vulnerable Isis line of communications across the desert, because that would have been "helping Assad".)
But the US air attack that went astray at Deir es-Zor last weekend was targeting Isis troops who were in direct contact with the Syrian army. It's because the two sides were so close together that the planes hit the Syrian troops by mistake. American diplomats still deny it, but the US is now willing to help Assad, at least sometimes.