The prime minister of Japan, Kishida Fumio, is keeping a laser-like eye on conflicts around the world—and the implications for his country’s security. If Russia is allowed to prevail in Ukraine, “it will send the wrong signal to Asia,” Mr Kishida told The Economist and other reporters in a wood-panelled room at the Kantei, the prime minister’s office, on April 5th. The desire to strengthen Japan’s security alliance explains why he went to the White House on April 10th for a state dinner with Joe Biden, America’s president. The two leaders announced a host of measures to deepen defence and security co-operation between their…