The trouble began when Indian media started reporting a "deep incursion" on April 15 in which a platoon of about 30 Chinese soldiers entered the Daulat Beg Oldi area in the Depsang Valley of eastern Ladakh in Indian-administered Kashmir.

Shrill media reports of Chinese incursions are not uncommon in India, where Sinophobia has been wired deep into the national psyche since a drubbing by China in a border war in 1962. Every time such reports appear, New Delhi's stock response is that it's a misunderstanding caused by "perceptual differences". This time is no different.

India and China do not have a real border marked out on the ground as they never got around to negotiating one. What they follow is an undemarcated Line of Actual Control (LAC), but each side has its own perception of where that line actually lies. As a result, it is not uncommon for patrols to stray into each other's territory. Years of painstaking talks have gone into creating an elaborate mechanism to prevent such transgressions from snowballing, keeping the peace for 25 years.

What is different this time is that none of the standard operating procedures that comprise this peace mechanism seem to be working. These procedures include waving banners to alert the other patrol if it is on the wrong side of the LAC, and meetings between local commanders. This time, two flag meetings have been held but the stalemate continues. New Delhi insists Chinese troops have entered 18 kilometres into Indian territory and must leave. Beijing maintains its soldiers are on the Chinese side of the LAC and won't budge. And, in an alarming show of strength, both sides have dug in, pitching tents to strengthen their claims.

The confrontation has sent diplomats into overdrive to calm tempers before Li's India visit as both sides have set much store by the trip. Bilateral trade, barely about US$3 billion in 2000 following decades of shutting each other out after the war, has now reached nearly US$80 billion, making China India's largest trading partner. The aim is to reach US$100 billion by 2015, with both sides looking for greater access to each other's markets. They are also increasingly working together in other areas, ranging from environment to energy security.

"Sino-Indian relations are developing very quickly. Li's visit will be his first foreign trip after taking office, and is in a complete break with protocol, showing the importance China attaches to relations with India," says Ma Jiali, an India expert at the China Institutes of Contemporary International Relations in Beijing.

Li's choice of India as his first port of call had created a burst of goodwill in India for its symbolism. Going by protocol, it was Indian Prime Minister Dr Manmohan Singh's turn to visit Beijing this year to reciprocate for former premier Wen Jiabao's tour in 2011.

Lei Guang, director of the 21st Century China Programme at the University of California, San Diego, also points to the upswing in ties, citing President's Xi Jinping's description of relations with India as "one of the most important for China" - an unusual focus for a new Chinese leader.

"China at this moment does not have anything to gain from asserting itself against India. If anything, as former Indian foreign minister Jaswant Singh puts it, China seems to pivot to Russia and India, even while it seems to adopt a more assertive attitude towards Japan and Southeast Asia," Lei says.

That makes this stand-off, and its timing, even more baffling. Coming as it does on the heels of the disputes in the East and South China seas, it only feeds the notion of an assertive China. That's at least how Dr Li Mingjiang , an assistant professor at S Rajaratnam School of International Studies in Singapore's Nanyang Technological University, reads it.

According to Li, Chinese and Indian armies have regular run-ins but the PLA is clearly showing more aggression this time.

"It might have been caused by the new leadership's assertive stance on issues of national interest. President Xi has publicly urged the army to spare no efforts to defend China's territorial integrity and core interests," he says. "Such high-profile political signals would only encourage the army, especially frontier forces, to toughen their own stance in local disputes."

Ashley Tellis, senior associate at the Carnegie Endowment for International Peace, also believes the PLA has upped the stakes. "This one dramatically changes the status quo as the Chinese appear to have physically occupied new territory under Indian control," he says, pointing out the Chinese picked an area where India has been attempting to ramp up defences.

India has recently reversed an ultra-defensive policy of not building infrastructure along the border lest it provides easy access to enemy forces. It is briskly laying roads and setting up airbases to catch up with dazzling Chinese facilities across the border that give China a far greater advantage in troop mobilisation should a conflict break out.

This buzz of activity close to the LAC hasn't gone down well with local Chinese troops, who often disrupt these construction works, in turn feeding the Indian media with more incursion stories. In Daulat Beg Oldi itself, India has reactivated an old landing strip, one of the world's highest, after nearly 50 years.

"Indians are building more outposts, which the Chinese of course do not appreciate. It's quite likely the Indian side is eager to show its resolve to the new Chinese leadership," says Professor Jonathan Holslag, head of research at the Brussels Institute of Contemporary China Studies.

Srinath Raghavan, the author of , shares the view that Chinese unease with India's border bustle is the big driver in this round of hostilities. But the senior fellow at the Centre for Policy Research in New Delhi refuses to divine a hardening of Beijing's overall stance towards India.

"I think it fits with past patterns of incursions in the area," says Raghavan. "The Chinese are operating within their notion of the LAC. There is evidently an increase in tit-for-tat moves but China is not the only active party here. We too make our moves in areas that fall under China's perceived LAC. So long as there is no agreed boundary, these things are bound to happen."

Dr Dibyesh Anand, associate professor at the University of Westminster, London, sees in the Indian response a familiar pattern of selective leaks from the security establishment and jingoistic media outrage. "I don't see a major policy change by Beijing. It's an initiative of local commanders, accentuated by familiar Indian brouhaha as if Indians don't make similar incursions."

"Local" is a word that New Delhi has also been using a lot to describe the incident. In the understated language of diplomats, a local military move is shorthand for one driven at field level for local tactical gains - as opposed to a top-down act of aggression, the way the media and the opposition parties are portraying it in India.

Stressing the "local" aspect of the crisis also reflects efforts to not let the border face-off "spill over into the larger spectrum" of bilateral relations, as Indian Foreign Minister Salman Khurshid puts it. The opposition is already urging Khurshid to cancel his trip to China next week.

"I would be surprised if this were a co-ordinated Chinese plan to establish a new presence," says Tellis. "I think the PLA, concerned by recent Indian efforts to upgrade its frontier defences, decided to establish a physical presence in the area. Any other explanation makes no sense because the new Chinese leadership is making a serious effort to keep Sino-Indian relations on an even keel, even if only to wean India away from the United States. The PLA does often pull in different directions from the civilian administration."

For Tellis, a co-ordinated military-civilian manoeuvre by China is not likely as India figures too low in Beijing's strategic priorities to merit such a venture.

According to Raghavan, there may even be a disconnect between the local Chinese military units and those at the top, not just between the PLA and the foreign office. "You will find such a disconnect surprising only if you believe that China always moves strategically, that it does not experience the usual problems of subordinate bureaucracies doing their own thing, and that the Chinese system doesn't have its fair share of muddle. No great power has ever functioned that way."

Smart money is on an eventual resolution, even if it takes a while. Driving India into America's arms makes very little sense for China and ratcheting up tensions with the next superpower makes even less sense for India.

China and India have realised they are strategic partners as they need each other on the international stage, says Dr Sun Shihai , a researcher at Chinese Academy of Social Sciences, Beijing. "Compared with their goal to be independent great powers, the border row is a small issue. Neither side will let it escalate."

Professor Simon Shen, director of the global studies programme at Chinese University of Hong Kong, agrees: "This incident won't jeopardise Sino-Indian commercial relations and their collaboration in the BRICS framework [the economic bloc made up of Brazil, Russia, India, China and South Africa]."

But if history is anything to go by, common sense doesn't always dictate Sino-Indian relations. Daulat Beg Oldi could be a pit stop before the two Asian giants resume their journey on a modern-day Silk Road, or before they return to their old inimical ways. A pit stop before China and India go back to making history, or repeating it.