Russian forces attempted to cross the Siverskyi Donets river in eastern Ukraine this month using a pontoon bridge, but their tanks and armoured vehicles were picked off by Ukrainian artillery. So they tried it again. And again. And again. The Russian army made nine attempts to cross the river in the second week of May, according to Ukrainian defence chiefs. Russia lost about 80 tanks or other vehicles and more than 400 men in the ill-fated operation … It is part of a pattern of Russian behaviour since the invasion began three months ago. By contrast, Ukraine’s forces have proved to be agile, using the leeway afforded to company and even platoon commanders to shape their tactics according to the conditions on the ground.