Necessity and Ukrainian ingenuity have combined to build a flourishing arms industry, almost from scratch, in just four years. Weapons expert Oleh Katkov, from the Defense Express consulting company, says Ukraine has multiplied its weapons-producing capacity 30-fold since Russia’s full-scale invasion.How have they done it? “We’re an open, creative society,” Katkov says. “And we are fighting for survival.”If Ukraine loses this war, he says, then all the territory from Kharkiv, on Ukraine’s eastern border with Russia, to Uzhhorod near the western border with Slovakia “will be turned into Bucha”.At Bucha, near Kyiv, the Russians murdered at least 458 civilians and...