Gently but firmly, the new commander of American forces in the Pacific has urged the South Koreans and Japanese to find a way to get past the demons of their history and to forge a new and productive security posture.

Adm. Samuel Locklear, who assumed command of the Pacific Command at its headquarters in Honolulu in March, encouraged the governments in Seoul and Tokyo “to find a way past the political divide that stops them from recognizing the importance of information sharing as it relates to the security environment.”

In an interview with several American reporters, the admiral said he and Pacific Command should ensure that the governments of South Korea and Japan, both treaty allies of the U.S., “are aware of the military imperative of information sharing and working together if you want to build a productive security environment.”

Locklear had been asked what he and Pacific Command could do about the long-standing Korean-Japanese hostility that made relations between them perhaps the weakest link in the U.S. security stance in Asia. Earlier this month, the South Korean and Japanese governments negotiated an agreement to exchange information on issues such as the threat from North Korea. Just before the pact was to be signed, however, virulent anti-Japanese protests erupted in Seoul and the signing was called off.

The bad blood between Korea and Japan is often attributed to Japan’s oppressive occupation of Korea for 35 years that ended with Japan’s surrender in World War II in 1945. But it seems deeper than that. Now, 67 years later, anti-Japanese sentiment appears to be stronger than fear of North Korea even though North Korea caused more death and damage to South Korea in the Korean War of 1950-1953 and has been a live threat ever since.

Among Koreans today are those who assert that they are surrounded by Russia, China, and Japan, with U.S. forces sitting on top of them; striking out against Japan is the easiest course to release their frustrations. Koreans seem envious of Japan’s economic, industrial, and technological success and often contend that their products “are just as good as the Japanese.” In education, museums, and historical sites throughout Korea, antagonism against Japan is relentlessly nurtured.

For their part, Japanese are often wary of Koreans, ignore the similarities in Japanese and Korean cultures, seem insensitive to Korean laments, and have sometimes engaged in what can only be labeled clumsy diplomacy. Occasionally, right-wingers and nationalists contend that Korea benefitted from Japanese rule and justify Japan’s imperial expansion as normal for that time of Western colonialism in Asia.

Some Americans with experience in Asia argue that the U.S. should insist that Japan and Korea settle their differences for the sake of mutual security. Michael McDevitt, a retired rear admiral who was once Pacific Command’s senior strategic planner, wrote several years ago that “the United States has invested little effort over the past decade in pressing both of its allies to overcome the past.” Contacted by email in Washington, he said: “There still is some room for US efforts.”

Admiral Locklear sought to be optimistic: “I think we are seeing opportunities for them [South Korea and Japan] to be more closely aligned with each other. To some degree, economics will push them closer together. Security issues in the region will push them closer together. Many [in both nations] are concerned about North Korea and nuclear proliferation.” For more than a decade, North Korea has been developing nuclear arms and has shown no sign of stopping.

Those nuclear weapons, the admiral said, “will force them to get closer together.” In addition, China and Russia have nuclear weapons aimed at Northeast Asia. The U.S. has pledged to South Korea and Japan that the American nuclear umbrella extends over both nations. North Korea has also been attempting to develop long range missiles to carry nuclear warheads. Asked whether North Korea had built a missile that could hit Hawaii, 4,600 miles away, the admiral said: “They have not yet demonstrated that capability.”

Locklear suggested, however, that his command was watching Pyongyang’s program intently. “Homeland defense,” he said, “is my No. 1 mission.”