WASHINGTON (AP) — U.S. intelligence officials warned American defense companies on Thursday to increase security precautions following several acts of sabotage in Europe that officials have blamed on Russia. The public bulletin issued by the National Counterintelligence and Security Center advised companies involved in defense work — particularly those providing support to Ukraine in its war against Russia — to step up their defenses in the face of Russia’s escalating aggression toward Ukraine’s allies. “Russia’s sabotage activities in Europe increase the risk to U.S.