In 2025, Japan and South Korea mark the 60th anniversary of their diplomatic relations, coinciding with the 80th anniversary of Korea's liberation from Japanese colonial rule.

The two nations were expected to celebrate these significant milestones while reflecting on the resolution of outstanding disputes, which was allegedly addressed in 2023 under South Korea's ousted President Yoon Suk-yeol and former Japanese Prime Minister Fumio Kishida, facilitated by pressures from the administration of former U.S. President Joe Biden.

However, current geopolitical shifts cast a shadow over these expected celebrations.

South Korea is currently experiencing deep internal divisions following President Yoon's suspension from duty and his subsequent trial for allegedly attempting a constitutional coup.

This political crisis is likely to persist, regardless of the outcome of the upcoming presidential elections slated for the next two months, where the left-leaning Democratic Progressive Party, led by the populist Lee Jae-myung, is favored.

Meanwhile, North Korea continues to issue threats and exhibits aggressive posturing, particularly following its military alliances with other countries.

Concerns have been raised regarding the unpredictability of the United States' foreign policy under former President Donald Trump, especially given the administration's erratic engagement with allies and recent contentious interactions with Ukrainian President Volodymyr Zelensky.

New trade policies proposed by the Trump administration have also raised alarms about potential adverse impacts on South Korea's export-reliant economy.

Should Lee Jae-myung ascend to power, there are expectations that relations between Tokyo and Seoul may further deteriorate.

Lee was vocally critical of President Yoon’s conciliatory approach to Japan in 2023, which was perceived as a response to U.S. pressures to ease tensions between the two nations amidst their joint efforts to counter China’s growing influence and North Korea’s threats.

Lee’s leftist political stance and history of opposition to Japan are well-documented, as he advocates for groups critical of Japan's historical actions and demands for appropriate reparations, claiming Japan's failure to adequately address its colonial past.

In Tokyo, sentiments are mixed regarding Lee’s potential presidency.

Some Japanese officials voice skepticism, while others express cautious optimism, suggesting that mutual concerns over threats from China and North Korea (and possibly Russia) may drive both nations to maintain a cooperative relationship while engaging in trilateral security efforts with the U.S.

Amidst these discussions, the issue of nuclear capabilities emerges, with conservative elements within South Korea advocating for the development of an independent nuclear deterrent in response to fears that the U.S. might withdraw security assurances, especially considering the perceived inadequacies of past U.S. leadership.

Notably, the Democratic Progressive Party has historically opposed nuclear armament for South Korea but may revise its stance under Lee’s leadership to gain traction against more conservative factions ahead of the elections.

This pivot would necessitate cooperative relations with both Japan and the United States, rather than escalating tensions.

If Lee Jae-myung is elected and pursues antagonistic relations with Japan, it could compel the Trump administration to facilitate a new summit between South Korea and Japan’s leaders.

Such a meeting may be crucial to reaffirm shared interests and address mutual concerns, similar to the 2023 Camp David summit hosted by Biden, which brought together Yoon Suk-yeol and Kishida.

The Trump administration would have a vested interest in ensuring the success of such a summit to preserve the South Korea-U.S.-Japan security alliance and prevent South Korea from drifting towards an anti-U.S. coalition in Europe.