The United States estimates that Russian casualties in Ukraine so far have reached around 15,000 killed and perhaps 45,000 wounded, CIA Director William Burns said on Wednesday, adding that Ukraine has also endured significant casualties. Nearly five months since President Vladimir Putin ordered an invasion of Russia’s neighbour, its forces are grinding through the Donbas region of eastern Ukraine and occupy around a fifth of the country. Burns, speaking at the Aspen Security Forum in Colorado, said those gains have come at great cost. CIA Director Burns estimates 15000 Russians KIA in Ukraine…