In 2018, Japan and South Korea nearly came to blows. Japan accused a South Korean naval vessel of locking its fire-control radar onto a Japanese maritime patrol aircraft. A radar lock is the final step before preparing to fire weapons.

The incident was just a symptom of deeper problems in Japan-South Korea relations, starting with toxic historical disputes that go back over 100 years. But the near-miss in 2018 had a more immediate cause: an unfortunate political mismatch. Liberal leaders in South Korea tend to dislike Japan; conservative leaders in Japan usually take a hard line on historical issues. That was exactly the ill-fated political combination at play in 2018.

Today, we once again have a staunch conservative in power in Japan and a liberal president in South Korea. But instead of trade embargos and radar locks, we’re seeing drum duets and sushi dinners. Japan’s Takaichi Sanae and South Korea’s Lee Jae-myung have been all smiles during their two summits thus far.

In a twist of geopolitical fate, these two formidable leaders have defied expectations. Despite deep-rooted historical grievances, this unlikely duo has found unexpected common ground, bringing Tokyo and Seoul closer together than ever before.

What changed between 2018 and 2026? And, maybe more importantly, will it last?

Today, we’re talking about the Japan-South Korea relationship: what’s held it back over the past 70-plus years, and how Takakchi and Lee – the ultimate odd couple – have managed to put the two U.S. allies on track to finally put their differences aside.