POKROVSK, Ukraine (AP) – European leaders blasted Russia’s decision to cut natural gas shipments to Poland and Bulgaria as “blackmail.” They said the cutoff and the Kremlin’s warning that it might cut shipments to other countries is a failed attempt to divide the West over its support for Ukraine. Russia’s decision to use its most essential export as leverage marked a dramatic escalation in the economic war of sanctions and counter-sanctions that has unfolded in parallel to the fighting on the battlefield. The tactic against the two EU and NATO members could eventually force targeted nations to ration gas. It could also deprive Russia of badly needed income to fund its war effort.