THE war in eastern Ukraine has quietened, for now. Its disparate factions have as much reason to keep fighting as to put away their guns. But a ceasefire signed on September 5th in Minsk is so far mostly holding. Ukraine’s president, Petro Poroshenko, does not want to fight an unwinnable war against Russia, which is the situation he would have been in had he pressed on with Kiev’s “anti-terrorist operation” in the east. His Russian counterpart, Vladimir Putin, is happy to see Donetsk and Luhansk turn into breakaway territories that can serve as instruments against Kiev.From the outset the Kremlin has been advocating a permanent ceasefire, not from humanitarian impulses but because it likes the idea of frozen conflict-zones in the east of Ukraine. The political mood in Kiev spurred Mr Poroshenko to press on as long as Ukrainian forces had momentum. But the incursion by Russian troops with heavy weapons in late August showed that Mr Putin would not allow Kiev a military victory. Without direct NATO aid, Mr Poroshenko felt forced to make a deal.In the short term this will seem like a victory for…