India and Pakistan share a 3,300 km border, a 75-year rivalry over Kashmir, and warheads that can reach each other’s capitals in under five minutes. Unlike a great-power exchange, neither side sits inside a nuclear alliance — so the model shows something distinct: a devastating regional war that the rest of the world watches without joining.
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.
Each run starts the same way — India launches a first strike on Pakistan — 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:
Estimated human cost: 4.3 million (typical run: 175,000–6.7 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.
What each side brings to the exchange, from the simulator’s arsenal data (SIPRI/FAS-derived estimates):
| Metric | India | Pakistan |
|---|---|---|
| Nuclear warheads | 160 | 165 |
| Avg. warhead yield | 200 kt | 40 kt |
| Delivery legs (triad) | 3 | 3 |
| Automated "Dead Hand" | No | No |
| Population | 1.4 billion | 220.0 million |
Who else gets pulled in?
No third country is reliably drawn in — this stays a war between India and Pakistan. That containment is exactly what makes a regional nuclear exchange different from a great-power one.