NATO Secretary General Jens Stoltenberg has said that “Russia must not use false pretexts for further escalation” in the Ukraine conflict. “Russia now falsely claims Ukraine is preparing to use a radiological ‘dirty bomb’ on its own territory,” the NATO boss said from aboard the aircraft carrier USS George HW Bush on which he was a guest. “NATO allies reject this transparently false allegation.” “Russia often accuses others of what they intend to do themselves. We have seen this pattern before. From Syria to Ukraine,” he added. “The world is watching closely.” Moscow had previously alleged tha…