BEIJING - At the end of Russian President Putin's three-day visit to China, he toured one of China's main attractions: Emperor Qin's burial grounds, where hundreds of life-sized terra-cotta warriors have been lined up in battle array since 221 BC. Had those clay soldiers a life of their own and marching orders, they just might have ruined the day and the legacy of Russia's head of state.

That is because Russia, of all the imperialist invaders that annexed China's territories by force, just got itself the largest piece some 1.45 million square kilometers, or four times the size of Japan and 2.6 times the size of France - as a farewell gift from China. After Putin returned home, Russia will get to keep all that fertile land for posterity, with China's agreement. Last Thursday, China and Russia signed an agreement in Beijing settling the border demarcation between the two countries, thus putting an end to their territorial disputes of the past 150 years.

Since the mid-18th century, China suffered a series of military defeats at the hands of Western powers such as England and France that were opening up new routes of trade. The victors didn't help themselves to the land of the weak Qing Dynasty, though they did wrest a few exceptions, such as the leases on Hong Kong and Macau. By contrast, Russia proved itself the master of diplomacy - wars, after all, are for the unsophisticated. Moscow talked Beijing into giving up vast tracts of land not on battlefields but in negotiation rooms, using scare tactics on what was then an uninformed, gullible and vulnerable China.

For example, when the French-English armies were advancing on the Chinese capital during the second Opium War of 1858, Russia persuaded China to surrender large areas of land to Russia. The argument was simple and effective: if China allowed Russia's presence in its northern Manchurian province, that would prevent the invading Europeans from the holy land that held the roots of the ruling Qing royalties. Salt was rubbed into the wound when the Russians cast themselves as the best friends of the victim; the Russian ambassador assured China that "the Russian army is in China not to bully but to serve".

Subsequent Chinese leaders were not as generous - with a notable exception. The warlords who went through the revolving doors at the Forbidden City adhered to their nationalist vows when they overthrew the Qing Court. As one, they refused to recognize "the treaties, conventions, agreements, accords and contracts entered into between the preceding government of China and Russia" because they were unfair to China. Chiang Kai-shek never gave up the fight to regain lost land, though to no avail. Mao Zedong was a nice man to neighboring Burma and India in border treaties, but his largess didn't extend to the country lying to the north. But his stand stemmed more from his resentment of his fellow communists in Moscow than from his patriotism. He was quoted as saying to the visiting US president Richard Nixon in 1972, "The Russians, including both czars and the red Soviets, have occupied too much of our land."

Deng Xiaoping appeared initially to be firm in his position against "unfair history". In May 1989, he reminded Soviet president Mikhail Gorbachev of Lenin’s promise not to resort to those unfair treaties as the basis of border demarcation talks. However, Deng contradicted himself in the same summit meeting when he proposed that talks nonetheless should proceed based on these treaties. In his own words, his vision for a solution consisted in "ending the past and looking toward the future".

That forward-looking attitude got the stalled negotiations going again. Within the next five years, China inked three successive treaties with Russia, agreeing on about 97% of the demarcation of the 4,300-kilometer-long Sino-Russia border. The remaining disputes are now settled, too, with the signing of this latest supplementary agreement last week, lending substance to the "no mutual territorial claims" clause in the 2001 China-Russia Friendship and Cooperation Treaty.

For sure, it is highly unlikely that the lost land will return to China's sovereignty after so many decades. When is the last time anyone has seen Russia coughing up what it has already swallowed? Ask Japan about its northern islands. But what weak countries usually do when they are powerless, in order to get the better hand, is to renew claims from time to time over what they believe is theirs until, they hope, the balance of power starts to change in their favor some day. Forfeiting territorial claims, even though the aggression took place a long time ago, in effect denies future generations a chance for "unification", a concept held so dear and sacred by the Chinese. Small wonder, then, that some overseas Chinese are already crying foul.

In fact, Beijing has surprised itself this time, given its record in dealing with Russians. Back when the Chinese Communist Party was still a branch of the Communist Internationale funded and controlled by Moscow, it had an obligation not to the Chinese people but to the Soviets, who had, in the best tradition of skillful, manipulative and shameless Russian diplomacy, ulterior designs on China.

When Josef Stalin felt threatened by the Japanese army crouching on China's land, he built up a buffer by engineering first the secession and later the independence of Mongolia from its suzerain - China. What did the Chinese communists say about that? "Bravo for the Mongolians, who have suffered too long under the reactionary, oppressive Chinese Nationalist government," raved the People's Daily. Accepting credentials from the new country’s ambassador on July 3, 1950, Mao congratulated Mongolia on its great achievement of breaking away from the previous government of China.

That was not Mao's best performance - that was yet to come. After Japan invaded and occupied China's Manchurian provinces in September 1931, the Chinese Communist Party issued a statement calling on the Chinese people to "take up arms and defend" - get this - "the Soviet Union" because "the invasion is a prelude to an imperialist war against the socialist Soviet Union". Ideology and convenience prevailed over national interests again when the Chinese communists hailed the Soviet-Japan 1941 Neutrality Treaty that recognized each other's de facto occupation of parts of China's territories. Mao Zedong described the treaty as a "matter of course that will benefit China in the long run".

How a loss could turn into a benefit still awaits explanation. That won't come any time soon, though. The Chinese foreign minister declines to disclose the details of the latest border protocol. Not only is he eating his own words about "willingly subjecting his ministry to supervision by the people", but also the very words "China-Russia border talks" are now filtered out on mainland's Internet portals, lest the masses object to the giveaway of territory.

Vodka and Mao tai are both powerful memory erasers, but it is worth noting that Emperor Qin's subterranean warriors were stationed for the same purpose as the Great Wall that Qin erected along his northern borders: to preserve the kingdom and keep the barbarians out. Would the old emperor be furious and turning now in his grave at his squandering and unrepentant sons who gave up China's land?