ROK principal deputy national security adviser Kim Tae-hyo recently floated the idea that Seoul and Washington expand their “intelligence alliance” to include Japan. This marks the first time a South Korean official has used the term “alliance” in the context of the country's partnership with Tokyo.

The rationale for potentially including Japan in the ROK’s intelligence-sharing pact with the U.S. is clear: North Korea’s missiles and nuclear weapons pose a threat to Seoul, Tokyo and the tens of thousands of U.S. forces stationed in both countries. China's growing influence and military assertiveness in the Indo-Pacific region are also driving the two rivals closer together.