There is a comfortable assumption in India's strategic community that the Pakistan-China relationship is transactional rather than strategic — that Beijing uses Islamabad as a pressure point against India but does not genuinely invest in Pakistan's long-term capability or stability. I have held this view myself, at various points in my career. I no longer do.

The evidence of the past five years has shifted my assessment. The China-Pakistan relationship has deepened in ways that go beyond the CPEC infrastructure projects that have dominated public analysis. It has deepened militarily, technologically, and — most significantly — in the domain of nuclear and missile cooperation in ways that directly affect India's security calculus.

Pakistan's J-10C fighter acquisition from China — the first export of a 4.5-generation Chinese combat aircraft — was a capability transfer that Indian defence planners have publicly acknowledged changes the air balance in the western theatre. The supply of PL-15 beyond-visual-range missiles to the PAF, and their reported use during Operation Sindoor in May 2025, demonstrated that Chinese military technology is not merely sold to Pakistan — it is integrated into Pakistani combat operations in real time. The question of whether Chinese technical advisers were present at Pakistani air defence facilities during Sindoor has not been publicly answered. It should be.

The nuclear dimension is the most concerning and the least discussed. US intelligence assessments have for years flagged Chinese assistance to Pakistan's nuclear programme — in warhead design, in delivery system guidance technology, and in the development of the tactical nuclear capability that Pakistan has positioned specifically to counter India's conventional advantage. This is not ancient history. It is ongoing.

What does this mean strategically? It means that when India plans for a contingency on its western border, it cannot treat the Chinese and Pakistani threats as independent variables. The two are coordinated — not necessarily in real time, not necessarily in every scenario, but structurally, in the sense that Pakistan's capability envelope is defined in significant part by what China chooses to provide. India's western deterrence must therefore be calculated against Pakistani capability that is, in effect, backstopped by Chinese technology and Chinese strategic interest.

India's response has been sensible in its broad outline — building military capability across both fronts, maintaining a two-front war doctrine, deepening the defence industrial base. But the pace of capability building on the western front must be calibrated not against Pakistani organic capability but against Pakistani capability as it is likely to evolve with continued Chinese support over the next decade.

The Pakistan-China axis is not a temporary alignment of convenience. It is a durable strategic partnership between two states that share a fundamental interest in constraining India's rise. India's strategic planning must treat it as such — not as a complication, but as the central organising fact of its security environment.

Sachin Aggarwal is the Editor of The Hind. The views expressed are his own.