With a shared sense of victimization and historical resentment toward Japan, South Korea and China have presented a united front against Tokyo’s hawkish security policy and refusal to repent for its past wrongdoings.

But their collaboration, most recently symbolized by the establishment of a memorial in Harbin of a Korean who assassinated Japan’s first prime minister, is a double-edged sword for Seoul, experts say.

Seoul should take caution not to inadvertently aid Beijing’s apparent strategy to counter the rearmament of Japan, weaken America’s network of regional allies and eventually gain primacy in East Asia, they said.

“China would undoubtedly like to reduce the U.S.’ security role in Asia over the longer term. To do this will require Beijing to convince other Asian states to distance themselves from Washington, using various forms of economic and diplomatic pressure,” said Stephen Walt, professor at the John F. Kennedy School of Government at Harvard University.

“The Republic of Korea should resist this pressure, because moving away from the United States and toward China will inevitably require Seoul to accept a subordinate position and not oppose China’s actions in any serious way.”

Beijing and Seoul have recently stepped up cooperation in verifying Japan’s imperialist rampage across Asia.

Earlier this month, the two opened a memorial hall, dedicated to Ahn Jung-geun, a South Korean independence fighter, in China. Ahn, who shot to death Japan’s first Prime Minister Hirobumi Ito in Harbin in 1909 as part of his anti-colonization campaign, has been venerated by both countries. Yet, Tokyo called Ahn a “terrorist,” further infuriating Seoul and Beijing.

Japan invaded and occupied parts of China in the 1930s. The bitter memories of the 1937 Nanjing Massacre, also known as the “Rape of Nanking,” still fuel Chinese enmity toward Japan.

Korea suffered from Japan’s 1910-45 colonization of the Korean Peninsula, during which Tokyo mobilized young Korean men and women for forced labor and sexual servitude and caused deep scars on Koreans’ psyche.

Despite historical records that corroborate the arguments of Japan’s war crimes, Japanese politicians have made remarks and action that seemed to justify, gloss over or whitewash Japan’s past aggression.

Last December, Japanese Prime Minister Shinzo Abe paid respects at the controversial Yasukuni Shrine, which honors Japanese war dead including 14 class-A World War II war criminals.

Pundits say that although South Korea may well denounce Tokyo for its lack of contrition, Seoul should not let the long-festering historical issues seriously limit bilateral cooperation in various realms including security collaboration to fend off North Korea’s nuclear and missile threats.

“In international politics, there are no eternal friends or eternal enemies. It is a very dangerous logic to take alop-sided foreign policy and move toward only one side, particularly when the region faces a long-term shift in its configuration of political and military power,” said Kim Heung-kyu, a professor of politics and diplomacy at Sungshin Women’s University.

“It would be ill-advised (for Seoul) to strain ties with Tokyo too seriously, and block the possibility of future cooperation with Tokyo. Taking into account crucial variables, countries should make more efforts to enhance their strained relations.”

Allowing for American troops’ forward deployment in key strategic bases in the Asia-Pacific, Japan is a potentially crucial security partner for South Korea in case of an attack from North Korea.

For the U.S., Japan is arguably the most important security partner to maintain the regional order, particularly as China becomes stronger and more assertive.

Given this, Seoul’s escalating friction with Tokyo and closer cooperation with Beijing may unnerve Washington, which has been seeking to beef up the triangular security cooperation with its core Asian allies of Korea and Japan, analysts said.

Amid Washington and Tokyo’s push for stronger security ties, Beijing is expected to further strengthen its relations with South Korea and other neighboring states, experts said.

“China would actively seek closer diplomatic ties with neighboring states as a way to head off what it perceives as an attempt by the U.S. and Japan to militarily encircle it,” said Suh Jin-young, professor emeritus at Korea University.

“To insulate itself from pressure by Japan and the U.S. and advance further into the world, improving relations with neighboring states will be of greater importance than at any other time for Beijing.”

When it comes to Asia’s history, Korea and China have not always been on good terms.

In the early 2000s, China launched a controversial national research program, known as “Northeast Asia Project,” which experts here criticized for distorting Korea’s ancient history concerning the kingdoms of Goguryeo (37 BC-AD 668), Balhae (AD 698-926) and Gojoseon (2333-108 BC).

The project frayed bilateral ties with South Koreans berating China for fabricating its history to expand its sphere of influence to the Korean Peninsula.

Given the geographical proximity and the large gap in aggregate national power, pundits have raised the possibility that should the U.S. lose its preeminence in Asia, Korea could fall under China’s influence.

In his 2012 book, “Strategic Vision,” Zbigniew Brzezinski, the former national security adviser to former President Jimmy Carter, listed South Korea as one of the “geographically most endangered states” along with Georgia, Taiwan, Belarus and several others.

In the book, Brzezinski said that should there be a decline in U.S. power, Korea would face painful choices: either to accept Chinese regional dominance or seek a much stronger, though historically unpopular, relationship with Japan.

Historically, Japan resisted its absorption into a Sino-centric regional order and sought to protect its political independence, while Korea, in close proximity with China, found it difficult to fend off Chinese influence.

By Song Sang-ho (sshluck@heraldcorp.com)