The UK is prepared to send troops to support NATO deployment and protect the alliance’s east flank if Russia invades Ukraine, Prime Minister Boris Johnson said on Tuesday. The promise came as Defense Secretary Ben Wallace told MPs that there were individuals already in Ukraine “linked to the Russian state in ways that are not conventional” and “that should give cause for concern.” But Johnson resisted the more hawkish proposal of sending NATO troops into Ukraine—a non-NATO state—maintaining economic sanctions remain “the real deterrent” of a potential Russian invasion. Making a statement in Parliament on Tuesday, the prime minister told MPs that more than 100,000 Russian troops are “arrayed” at Ukraine’s eastern border—”far bigger than anything Russia has deployed” against Ukraine before. He said the British army “leads the NATO Battlegroup in Estonia and if Russia invades Ukraine,” while Denmark is sending a frigate to the Baltic and four fighter jets to Lithuania, …