NAVAL STATION PEARL HARBOR, Hawaii—In his first major speech as Pentagon chief, Lloyd Austin on Friday called for developing a “new vision” for American defense in the face of emerging cyber and space threats and the prospect of fighting bigger wars. Reflecting President Joe Biden’s promise to put diplomacy first in dealing with foreign policy problems, Austin said the military should provide leverage that diplomats can use to prevent conflict. “U.S. military isn’t meant to stand apart, but to buttress U.S. diplomacy and advance a foreign policy that employs all of our instruments of national power,” Austin said. He chose to spell out his ideas at Pearl Harbor, at the center of U.S. military power in the Indo-Pacific region, reflecting U.S. concerns that the Chinese communist regime’s rapid military modernization and growing aggression make it a powerful adversary. Notably, Austin in his speech did not explicitly mention China or North …