WSJ's Jeremy Page looks at Admiral Wu's efforts to build U.S.-China naval ties through relations with Admiral Jonathan Greenert, head of U.S. Naval Operations. Admiral Wu has the backing of Chinese president Jinping to expand the influence and capabilities of China's Navy. A skeptical Senate Armed Services Committee led by Senator John McCain sees the effort to enroll Chinese officers at U.S. naval colleges, and offers of visits to Chinese ports by U.S. aircraft carriers, as a ways to increase the capabilities of China's Navy. McCain and members of Congress are alarmed by the effort to build China's naval power on the Spratly islands to extend control over the South China Sea and beyond. Wu is the only naval leader on the 11 man China Central Military Commission, headed by president Jinping, which commands China's armed forces. He joined the People's Liberation Army in 1964 and in 1988 has commanded a group of destroyers. Wu as an advocate for a greatly expanded mission for the Chinese Navy following what is called the "century of humiliation" with the Opium War in 1842, is seen with wariness with close neighbors Taiwan, the Philippines, Vietnam, Japan, Australia and India....