China's support of North Korea grounded in centuries of conflict

Seoul, South Korea (CNN) -- Having just enjoyed Thanksgiving dinner, the American soldiers were told they would be home by Christmas as they launched their final offensive.

In fact, they were driving into the greatest ambush in modern history.

Twelve miles to their north, 380,000 brilliantly camouflaged enemy fighters lay in wait. In the days that followed, the U.S. Army would suffer its most harrowing ordeal of the past half-century.

Two American regiments were massacred at a pass called Kunu-ri; another was annihilated beside a frozen lake called Chosin.

The time was 60 years ago; the battlefield was North Korea; the enemy was China's People's Liberation Army.

Despite wide-ranging global changes -- the fall of European communism, the end of the Cold War, China-U.S. rapprochement, the rise of China as economic superpower -- there has been no indication that Beijing has altered its stance toward maintaining the isolated regime in the peninsula's north since it routed U.S.-led United Nations forces in Korea in the winter of 1950.

"China does not want to lose North Korea as a buffer zone vis-a-vis a pro-U.S. country -- South Korea," said Kim Won-ho, dean of the Graduate School of International Studies at Hankuk University of Foreign Studies.

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"The last thing China wants to see is U.S.-style democracy in North Korea," added congresswoman Song Sun-young, who sits on the South Korean National Assembly's Defense Committee. "Even if they apply open-door policies to their markets, China wants North Korea to follow the Chinese style."

While it is globally fashionable to view today's China through an economic lens, it is geopolitics, not economics, that lies behind Beijing's continued support of North Korea: The strategic position of the peninsula has not changed for millennia.

"Korea has always been a dagger into Russia, and an invasion and penetration route between Japan and China," said Kim Byung-ki, a security expert at Korea University. "This is why China has always had this important interest in the peninsula."

History seems to prove it. The Mongol rulers of China unleashed two 13th-century assaults on Japan from Korea. Japan launched a 16th-century invasion of Ming China via Korea. The first Sino-Japanese War, from 1894 to 1895, was largely fought in Korea.

In the past century, the Russo-Japanese War of 1904-1905 was over control of the peninsula. Japan used Korea as a springboard to seize Manchuria in 1931, from whence it assaulted China proper in 1937. Finally, the Korean War brought U.S. troops close to the Chinese border in 1950.

Today, the United States has replaced Russia and Japan as China's key regional competitor in Asia, Kim said, and the United States is encircling China with a range of moves and alliances -- with Afghanistan, India, the ASEAN regional forum, South Korea, Japan, and even Russia -- all backed up by the power of the Seventh Fleet.

"China will be a rising power for the next 10-15 years," Kim said. "But it understands it has problems with this encirclement."

In this context, North Korea, in addition to its strategic position on China's doorstep, is a rare voice of support buttressing China's historical role at the heart of Asia.

"In the past, China never accepted Korea or Mongolia or Vietnam as independent countries; they were vassal states, subject to Chinese power," said Lim Jie-hyun, a history professor at Hanyang University. "There is continuity and discontinuity, but (for China) to make a hegemonic block in northeast Asia, it needs other voices, and that voice is represented by North Korea."

Although the bellicose, isolated regime is a massive diplomatic embarrassment for China, Beijing's stance toward it fits with its policy toward other neighbors -- a policy that prioritizes stability.

"Some of the reasons for China's excessively moderate rhetoric is consistent with what it would have to do to maintain stable relations with any regime," said Bob Broadfoot, head of Hong Kong's Political and Economic Risk Consultancy. "China has a policy to maintain smooth relations with countries on its borders; it has more countries on its borders than any other country in the world."