Pakistan vs India: How a Nuclear War Would Unfold

Pakistan is the mirror image of the India scenario, and the differences matter. Its arsenal is smaller and its warheads lower-yield, but its doctrine is the more dangerous of the two: unlike India, Pakistan reserves the right to use nuclear weapons first, to offset India’s conventional superiority. The model shows how a Pakistani opening reshapes the same regional war.

LIMITED NUCLEAR EXCHANGE
Most likely outcome across 500 simulated runs of the escalation model

Nuclear weapons are used, but the exchange stays regional or tactical rather than becoming a full strategic war. The taboo is broken and thousands to millions die — the world steps to the brink and pulls back.

Simulated outcome

Each run starts the same way — Pakistan launches a first strike on India — and then the escalation engine plays the alliance cascade forward, decision by decision. Because retaliation, alliance loyalty and doctrine are probabilistic, the 500 runs don’t all end the same way:

LIMITED NUCLEAR EXCHANGE 100%
100%
Runs ending in limited nuclear exchange
5
Nuclear-armed powers drawn in
11
Nations drawn into the war
6.8 million
Direct strike casualties (median)

Estimated human cost: 6.8 million (typical run: 4.4 million–9.9 million).

Modeling note: these pages show the engine’s projected escalation, assuming launched weapons reach their targets. The live 3D simulation additionally rolls probabilistic missile-defense interception, so an individual run there may be less severe. Casualty figures are first-order estimates from capital-population and arsenal data — a floor, not a ceiling.

Arsenal face-off

What each side brings to the exchange, from the simulator’s arsenal data (SIPRI/FAS-derived estimates):

MetricPakistanIndia
Nuclear warheads165160
Avg. warhead yield40 kt200 kt
Delivery legs (triad)33
Automated "Dead Hand"NoNo
Population220.0 million1.4 billion

The alliance cascade

A strike is never just between two countries. These are the nations the model most reliably pulls into the Pakistan–India war (share of runs in which each is drawn in):

Germany88%Australia87%Canada87%France87%Italy87%Japan87%South Korea87%United Kingdom87%United States87%

Alliance clauses triggered

No alliance clause reliably triggers

The closest we’ve come

Kargil Crisis, 1999 — India and Pakistan came close to nuclear exchange. Both sides had deployed nuclear-capable missiles.
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