The spat began December 20 after an encounter between a Japanese plane, which Tokyo said was collecting intelligence, and a South Korean destroyer, which Seoul said was on a humanitarian mission.
Both sides disagree on what happened next -- the Japanese said the South Koreans targeted their aircraft with missile-targeting radar, while the South Koreans said the Japanese plane was flying dangerously low and that the radar "was not intended to trace any Japanese-controlled aircraft."
The disagreement has quickly escalated, bringing to the fore historical disputes previously on the back-burner and -- in turn -- threatening the region's stability.
