For the first time since the U.S. created an international group to coordinate military aid to Ukraine three years ago, America’s Pentagon chief will not be in attendance when more than 50 other defense leaders meet Wednesday. Defense Secretary Pete Hegseth, who returned from a national security conference in Singapore on Sunday, will not arrive in Brussels until Wednesday evening, after the Ukraine Defense Contact Group’s meeting is over. A U.S. official, speaking on condition of anonymity to discuss scheduling details, confirmed that Hegseth also will not participate by video conference. It is the latest in a series of steps...