An escalation in tensions between India and Pakistan is likely to increase Chinese support for Pakistan and add impetus to India’s strategic partnership with the United States, further polarising the subcontinent geopolitically and increasing the nuclear threat in the region.

China is now expected to raise its already substantial defence cooperation with “all-weather friend” Pakistan and possibly resume transfers of strategic weapons technology that were officially ceased in the 1990s under US pressure.

Why China is caught in India-Pakistan crossfire

“The conventional wisdom is that China will intensify support to Islamabad amid rising India-Pakistan tension,” said Michael Kugelman, senior associate for South and Southeast Asia at the Woodrow Wilson Centre, a Washington think tank.

“China will want to reiterate its commitment to Pakistan and express its strong support, particularly if Beijing starts to worry that India’s more muscular approach towards Pakistan could entail efforts to undercut or even sabotage the China-funded China-Pakistan Economic Corridor project.”

The US$46 billion trade route running from Pakistan’s Gwadar port on the Arabian Sea to China’s Xinjiang (新疆), is a “One Belt, One Road” initiative designed to expand China’s economic and political outreach in Asia as well as provide its landlocked, backward western provinces a sea route for trade.

After cross-border military raid, India looks at more ways to pressure Pakistan

Tensions between India and Pakistan have been rising since last month, when 18 Indian soldiers were killed by a militant strike on an army base in India-administered Kashmir. India blamed the attack on Pakistan-based militants and within days launched a retaliatory “surgical strike” on alleged militant bases on the Pakistani side of the Line of Control, the de facto border between the two countries.

Pakistan has denied any complicity in the militant attack on the Indian army base and has also denied India’s “surgical strike” ever took place, but that has hardly helped matters, with fears rising over a fully fledged conflict between the nuclear-armed neighbours.

India’s ‘surgical strike’ claim in Kashmir dismissed by Pakistan

China and the US have voiced concern over the latest hostilities. But beyond the immediacy over the current crisis, both essentially view South Asia through the wider lens of strategic competition in Asia, particularly Beijing’s rising assertiveness in the South and East China seas and the Obama administration’s efforts to contain the rising superpower.

This strategic calculus resulted in a breakthrough in relations between the US and India in June, when Washington decided to grant New Delhi “major defence partner” status. Potentially, it opens the way for substantial transfers of US military and so-called “dual-use” technologies that can be used in Indian strategic weapons such as ballistic missiles.

“The nuclear arms race in South Asia has its own logic but China’s growing military sophistication has pushed India and the US closer, which has further cemented the China-Pakistan alliance,” said Harsh V Pant, professor of international relations at King’s College London. “This has implications for the nuclear dynamic as well.”

India signs deal for 36 French fighter jets to counter China, Pakistan squadrons

The stakes were raised again on August 30, when India and US signed a logistics sharing pact under which their militaries can use each other’s bases, such as the US base at Diego Garcia in the Indian Ocean, where Chinese submarines are becoming noticeably active.

China and India fought a war in 1962. Like Pakistan, China also shares a disputed border with India, and has long been Pakistan’s steadfast strategic ally.

Before the escalation in Kashmir, security experts told This Week in Asia that China would be tempted to retaliate against the US-India agreement by resuming strategic weapons technology transfers to Pakistan.

“China has provided extensive assistance to Pakistan in the past and this is well documented,” said Christine Fair, an associate professor of security studies and South Asia expert at Georgetown University in Washington.

Indian Prime Minister Narendra Modi takes aim at Pakistan and governments ‘inspired by terrorism’

Experts said the physical appearance of the transport erector launcher used by Pakistan in December 2015 to test its Shaheen-3 intermediate-range ballistic missile, capable of striking anywhere in India, was similar to a launcher transferred to North Korea by China in 2011.

Beijing is also said to have strengthened Islamabad’s hand in response to Indian tests of two variants of intercontinental ballistic missile (ICBM), the Agni-V and Agni-VI. Both are being developed to deliver several nuclear warheads at a time, using multiple independent re-entry vehicles (MIRV). China last year introduced 10 MIRV variants of its DF-5 ICBM.

Kashmiris warn India its crackdown is turning more young people towards militancy

Seeking to match India’s development of second-strike capabilities through land, air and sea-based delivery systems, Pakistan in 2014 formally requested China to transfer technology so it could build its own ballistic missile submarines. A deal was concluded last October for Pakistan’s acquisition of eight Type 041 diesel-electric attack submarines that would be armed with Pakistan’s nuclear-capable Babur cruise missile.

Unlike China and India, Pakistan has refused to adopt a “no first strike” posture. However, the expansion of all three countries’ nuclear forces had created a situation whereby India might have to rethink its nuclear doctrine, which is based on a “no first strike” principle backed by the threat of massive retaliation, experts said.

“India should be trying to secure dominance, given recent Pakistani decisions with respect to its strategic systems,” said Fair.

Caught in the middle: Kashmiri police face public wrath amid anti-India uprising

The advances in the strategic weapons programmes of China, Pakistan and India had significantly raised the danger of nuclear conflict because they threatened “to blur nuclear thresholds and elevate the risk of inadvertent nuclear escalation due to misperception”, according to a study in June by the US Strategic Studies Institute and Army War College Press.

India’s official public nuclear doctrine, which had “not been updated since 2003” in line with the changes in the technological and strategic environments, provided “further ambiguity and risk”, it said.

Tom Hussain is an Islamabad-based journalist and Pakistan affairs analyst