At the gun station at Penga Teng Tso, Indian soldiers keep a close watch at the expansionists

The Line of Actual Control is more unstable than it sounds like, and recent shows of force have raised concerns about what two nuclear nations might do there next

India is finding itself at the forefront of an international effort to contain an ascendant, increasingly aggressive China, with New Delhi playing a big role in a formerly dormant diplomatic alliance in the process of transforming itself into a military one.

As the two nuclear powers – and world’s most populous countries – dial up the rhetoric and flex their muscles in a long-simmering dispute over their long, nebulous border, the situation risks boiling over again and has pushed India closer to the West in its dealings with China – an extraordinary pivot for a country that was once a leader of the “non-aligned movement,” a forum for countries that wanted no part of the polarized world of the Cold War.

Last week India test-fired a nuclear-capable intercontinental ballistic missile, with one of the country’s broadcasters reporting the news under the banner “Dragon put on notice.”

The missile had a range of more than 5,000 kilometres and a high degree of accuracy, significantly increasing the reach of India’s nuclear deterrent.

Tensions between Delhi and Beijing have been ramping up after a period of relative calm since a clash between Indian and Chinese troops high in the Himalayas last year that left at least 24 dead. Military-to-military talks broke down in early October, with both sides blaming the other for their failure.

An editorial in the Global Times, a nationalist state-run tabloid close to China’s military establishment, said the dispute’s “root cause is that Indian side still hasn’t developed a correct attitude in the negotiations.”

The most recent dispute has involved the Galwan Valley, which lies between Indian-administered Kashmir and China’s Tibet Autonomous Region, at the western edge of the two countries’ 3,380-kilometre border, or “Line of Actual Control” (LAC).

Since talks broke down, there have been reports of troop movements on both sides, and Chinese state media have broadcast videos showing its forces’ capabilities, though the onset of the brutal Himalayan winter means imminent conflict is unlikely, with troops focused on digging in against the cold.

Previous spats have focused on the eastern sector and the Siliguri Corridor, or “chicken’s neck,” which connects the bulk of India’s territory with its most north-eastern states. This sensitive chunk of land butts up against not only China but also Bhutan and Nepal, both of whom Beijing has been accused of pressuring in recent years.

The LAC stems from the Sino-Indian War of 1962, from which China emerged largely victorious. Since then there have been numerous minor conflicts and accusations from both sides that the other is illegally building on or fortifying their side of the boundary. “This territorial dispute has been lasting for almost 60 years, and all signs are that it will continue,” said Frederic Grare, a senior Asia policy fellow at the European Council on Foreign Relations. “Much more than the territory itself, both sides consider it vital to demonstrate their capability to resist or pressure the other.”

So far, China largely has the upper hand. While the People’s Liberation Army (PLA) withdrew some of its troops in the wake of last year’s clash, it has retained most of the ground it gained, leaving India to negotiate its way back to a status quo that already wasn’t to Delhi’s liking.

“The Chinese objective is to keep the Indians off balance,” said Gurpreet Khurana, a professor at the Indian Naval War College in Goa. “It keeps India in a place where it cannot grow out of its immediate national security threats” and challenge China in other areas.

“We as a nation need to invest more in opening up our maritime links, but this is exactly what the Chinese don’t want,” Dr. Khurana said, pointing to China’s increased presence in the Indian Ocean and its engagement of smaller countries in the region. “Any adversary of power which can dominate or displace Indian influence in this area would have India at its mercy,” he added. “Some people in India see this as the Chinese encircling us, and while I don’t think this is necessarily the end objective, the effect is the same – and that is a serious concern.”

Speaking in January, Indian Foreign Affairs Minister Subrahmanyam Jaishankar said the China-India relationship was left “profoundly disturbed” by the events of 2020. “After 45 years, you’ve actually had bloodshed on the border,” he said. “And that’s had a huge impact on public opinion and politically” in terms of “trust and confidence in India where China and their relationship is concerned.”

Mr. Grare said that, in recent years, “there were no carrots at all” in Beijing’s treatment of Delhi, even as India remained an important trading partner and potential market for Chinese goods. China has largely treated its huge neighbour as it does far smaller countries in the region: with neglect or, at best, ambivalence.

The result has been a pivot by Delhi, which has always prided itself on its independent foreign policy, toward Washington. In July, U.S. Secretary of State Antony Blinken travelled to India to reaffirm the two countries’ “strong strategic partnership founded on shared values and a commitment to a free and open Indo-Pacific region.”

India is a member of the Quadrilateral Security Dialogue, or Quad, an informal strategic forum that also counts the U.S., Japan and Australia as members. While largely dormant for many years after its founding in 2007, the Quad was revived in 2017 and has emerged as a major player in the Indo-Pacific, with the U.S. in particular pushing for it to evolve into something like an Asian NATO – with the aim of containing China.

Last year, “in the light of increased defence co-operation,” India invited Australia to join the regular Malabar naval exercises it holds with the U.S. and Japan, the first time in 13 years that all four navies of the Quad have taken part in a joint drill. In a statement, the Indian navy said the participants “collectively support a free, open and inclusive Indo-Pacific and remain committed to a rules based international order.” Such language is typically directed at China, which claims large swaths of maritime territory unrecognized by international law and frequently objects to “freedom of navigation operations” carried out by other countries in those waters.

But Dr. Khurana said “the Quad cannot function in a manner that the Americans envisioned – not with a country like India, which has an independent foreign policy and doesn’t like military alliances. - “That is why AUKUS has come into being.”

A new alliance between the United Kingdom, Australia and the U.S., AUKUS is focused on military capability and technology sharing, allowing Australia to acquire new long-range strike capabilities for its air force, army and navy, as well as nuclear-powered submarines. It was formed after Washington described the Indo-Pacific as “the single most consequential region for America’s future” and stressed the need to contain China’s ambitions.

Dr. Khurana said the Quad and AUKUS could play complementary roles, along with diplomatic platforms such as ASEAN and the East Asia Forum. “All of these are tools,” he said. “And if persuasion is not possible and you need to deter [Beijing], then you have a potential military response from AUKUS.”

The provision of new submarines to Australia prompted China to warn of a potential “nuclear arms race” and question Canberra’s commitment to disarmament, though the subs are only nuclear-powered and do not carry atomic weapons. Any dispute between India and China also raises such a shadow. In recent weeks, China reportedly tested a hypersonic missile system, and new missile silos have been spotted in its Xinjiang region.

Most analysts agree that a serious arms race, let alone a nuclear conflict, is very unlikely. Even last year’s deadly clash, which saw the first fatalities since the 1962 war, was fought with clubs and fists, the result of a longstanding policy that soldiers on the border not carry guns.

“The fact that it took the form that it did is clear evidence there was no willingness to escalate, even at the time,” Mr. Grare said. “The fact that the two countries are nuclear powers – short of a mistake and sudden escalation in which no one has anything to win – does limit the conflict potential between the two.”

Dr. Khurana agreed, saying that the risk of nuclear conflict can sometimes be a big distraction from other activities, such as so-called “grey zone” quasi-military actions by China along the border.

“Below the nuclear threshold there’s a lot which can be done, and the Chinese are already doing it.”