Things might have been a little awkward when Chinese President Xi Jinping and Indian Prime Minister Narendra Modi saw each other on the sidelines of the Group of 20 meeting in Germany. Far from the plush leaders events in Hamburg, China and India are facing the resurgence of a decades-long dispute over a remote area of the Himalayas. The interruption of summits by such tensions is a regular event, but both sides are now invoking memories of a 1962 border war in which Maoist China defeated newly-independent India. While the latest flareup is likely to be resolved diplomatically, it adds to an increasingly fraught relationship between the nuclear powers as they jostle for influence in South Asia. India’s fast-growing economy is fueling its ambitions and ties to the west, while Beijing is asserting territorial claims in the East China Sea, South China Sea and remote Himalayan passes. Xi and Modi addressed an informal meeting on Friday of leaders of the BRICS—Brazil, Russia, India, China and South Africa—nations, which was held alongside the G-20 summit. There were no plans for a direct sit down. Both leaders told the BRICS gathering that member countries needed to remain committed to an open global economy and fighting climate change. They did not mention the acrimonious border conflict. “It has to be seen as part of a larger pattern, where they are becoming assertive, and they’re getting into this habit of enforcing their claims that are contested, and sometimes imagined, disregarding the views of others,” said Ashok Kantha, a former Indian ambassador to China and head of the Institute for Chinese Studies in New Delhi.  The countries disagree over who started the most recent skirmish and what happens next, with both sides declining to back down. BRICS Summit Some China observers say Indian troops crossed the border—around the time Modi met U.S. President Donald Trump in Washington, and ahead of the G-20—to remind the world that India is able to contain Chinese ambitions. In China, it’s particularly sensitive because it comes before China hosts a major BRICS summit in September that was personally endorsed by Xi. “Both China and India are rising powers, but apparently China’s development is faster and it has greater global influence,” said Zhou Gang, a former Chinese ambassador to India. “India is not comfortable with that. They are jealous,” Zhou said. “When the Indian government wants to stir up its nationalism, China becomes the easiest target.” New Delhi is wary of Beijing’s infrastructure projects in Pakistan and other neighboring countries. At the same time, Beijing is seeking to build its clout through its Belt and Road trade initiative and believes India’s resistance reflects a fear of China’s rise. Stand-offs between India and China have occurred in the past, including when Xi visited New Delhi in 2014. In recent years, both sides have sought to build roads and other infrastructure leading up to their shared border.  The current dispute is at a three-way junction between Bhutan, China’s Tibet and India’s Sikkim.  Bhutan’s Foreign Ministry said a Chinese road-building party crossed into its territory on June 16. India later said Bhutanese troops attempted to dissuade the People’s Liberation Army-escorted construction team. After that failed, Indian personnel in the region approached and “urged them to desist from changing the status quo.” Chinese Foreign Ministry spokesman Geng Shuang said Indian troops crossed into China, “breaching” historical conventions and violating international law.  “It is the Indian side who takes ‘protecting Bhutan’ as an excuse to justify its boundary-crossing and entry into China,” he said in a briefing on Thursday. ‘Look Down’ India’s Defense Minister Arun Jaitley, alluding to India’s painful loss more than half-a-century ago, said the India of today is different. Army chief Bipin Rawat visited the area, and earlier in June—just before the stand-off—said his forces could cope with a multi front war against China and Pakistan, according to a Times of India report.  For its part, China’s state-owned Global Times said in an editorial the Chinese “look down” on India’s military and “India will suffer greater losses than in 1962 if it incites military conflicts.” In remarks to the Press Trust of India, China’s current ambassador to India said the situation was “grave” and India’s troops must pull out before there are any talks. The ambassador did not rule out a war. “There has been talk of that option,” he was quoted as saying. “The trouble is, this stand off is really one where the Chinese have said they will clearly not back down,” said Alka Acharya, an international relations professor at Jawaharlal Nehru University in New Delhi. “In earlier standoffs, they were looking for a face saving device, where they can go back to the status quo.” The risk is the border tensions become further entrenched in the bigger tussle for influence.  “It reflects a broader deterioration in the relationship, and reflects some sort of a concern that India is taking a more aggressive stance,” said Harsh Pant, a professor of international relations at King’s College London. “India is the only major power that is standing up to China on multiple levels.”