Amid all the media focus on China's maritime territorial disputes with Japan, Vietnam and the Philippines, the world nearly forgot that China still hosts the world's largest outstanding land border dispute with the world's largest democracy, India.
This author just returned from a week of meetings in Beijing, where China's territorial disputes were at the top of our delegation's agenda; the border dispute with India was conspicuously absent from our discussions.
As if on cue, however, on April 15, the territorial dispute that brought the two sides to war in 1962 reared its ugly head again. That day, an armed Chinese patrol supported by a helicopter reportedly moved 10 kilometers across the Line of Actual Control (LAC) and pitched several tents in northeastern Ladakh, near Daulet Beg Oldi.
Three "flag meetings" between Chinese and Indian military commanders have failed to dislodge the People's Liberation Army (PLA) patrol, which is now being re-supplied.
With luck, the two sides will utilize the elaborate diplomatic mechanisms in place at the border and the mini-crisis will gradually fade from the headlines. But there are escalation risks. So far, only a small contingent of the paramilitary Indo-Tibetan Border Police has been sent to the area but if the PLA patrol lingers, it's only a matter of time before the Indian Army follows.
One must go back to 1967 to find the last deadly exchange of fire across the LAC. Since that episode at Nathu La, the border has been free of violence, but not of violations.
It's no mystery why: With the exception of the relatively minor "Middle Sector," China and India have yet to define their respective boundary claims through a basic exchange of maps.
This creates a volatile situation where, according to Indian analyst Zorawar Singh, "there is no mutual agreement on where Indian and Chinese troops have the legal right to be positioned."
Lt. Gen. HS Panag, the former head of India's Northern Command, has suggested there are as many as nine mutually accepted areas of differing perceptions of the LAC.
The Indian media reports there have already been more than 100 PLA transgressions across the LAC in the first quarter of 2013. This tracks with Indian Home Ministry figures citing 228 transgressions in 2010 and 213 in 2011.
Such reports send the opposition and the Indian public into a furor. Yet the Indian government and military officials regularly insist the border is peaceful and free of Chinese intrusions.
The conflicting messages result from a poorly explained distinction New Delhi makes between "intrusions" (intentional breaches of Indian sovereignty) and "transgressions" (inadvertent breaches of the LAC, based on different perceptions of the boundary line).
In 2012 India's home minister explained: "There has been no intrusion along the India-China border. However, there are cases of transgression due to different perception of the LAC."
Most of the transgressions are undoubtedly innocent violations of an unmarked border, and it's unclear how guilty Indian patrols are of similar violations because China doesn't keep count.
"If we make the calculation on our understanding of the LAC, maybe the Indian border troops have transgressed the line more than what the Chinese border troops have done," said Maj. Gen. Yao Yunzhu of China's Academy of Military Sciences.
But Beijing is guilty of allowing an environment of petty adventurism by its border patrols. A few times a year, Chinese patrols go beyond the usual transgression to destroy a structure or spray-paint "China" on rocks on the Indian side, though they always return to China's side of the LAC.
That's what makes the current situation troubling: Instead of returning to their base camp, the Chinese patrol has stayed put. By the Indian government's own definition this is not a transgression but a genuine intrusion, perhaps the first major intrusion since 1986, when the two sides nearly went to war over a similar episode at Sumdorong Chu.
The most likely explanation is that China is signaling its displeasure toward the quiet but substantial improvement of India's military infrastructure along the LAC, where recently erected border posts may have triggered a brash reaction from Beijing.
Many Indians hold a less charitable view. "China's strategy is evident," said Indian analyst Ajai Shukla. "To confine Indian strategic attention to the Sino-Indian border, preventing New Delhi from looking beyond at Tibet and Xinjiang, China's most sensitive pressure points." China has been known to apply pressure at the border when it is feeling insecure in Tibet, and a wave of self-immolations by Tibetan monks in recent years — now over 100 — has put Beijing on the defensive.
A more worrying explanation, however, was hinted at during an American Foreign Policy Council delegation to Beijing April 14-21. There, we heard that some of China's increasingly vocal nationalists were describing China's standoff with the Philippines over the disputed Scarborough Shoal last year, where China deployed and then permanently based armed vessels at the shoal, as a "model" for its territorial disputes writ large. The lesson, they gathered, was to "change facts on the ground and worry about the consequences later."
China seems to be flirting with a similar strategy in the Diaoyu/Senkaku islands dispute with Japan. If this intrusion signals an aggressive new Chinese posture at the border rather than an isolated incident, it would constitute a dangerous new dynamic for Sino-Indian relations.
Jeff Smith, the Kraemer Strategy Fellow at the American Foreign Policy Council and author of a forthcoming book on Sino-Indian relations, from which parts of this piece are drawn.