Last week, South Korea announced that it would end the General Security of Military Information Agreement (GSOMIA) which was signed with Japan only three years ago. While many people in Tokyo and some in Seoul wondered why South Korea made such a move, it was shocking but not surprising.

The reason is crystal clear: Neither Tokyo nor Seoul can now back off for domestic political reasons, while Washington remains unwilling, or probably unable, to mediate for its two East Asian allies. What's most worrisome, however, is the suffering of the foreign policy/national security establishment in both Seoul and Washington.

Silence seems to be golden in South Korea. This kind of sudden and bold national security decisions would never have been made in 20th-century South Korea. There are great strategic thinkers and competent foreign policy/national security experts in Seoul but most of them will not speak out. Why?