If India and Pakistan fought a war detonating 100 nuclear warheads (around half of their combined arsenal), each equivalent to a 15-kiloton Hiroshima bomb, more than 21 million people will be directly killed, about half the world's protective ozone layer would be destroyed, and a "nuclear winter" would cripple monsoons and agriculture worldwide.
21 million people will perish
According to the study by researchers from Rutgers University, University of Colorado-Boulder and University of California, Los Angeles, about 21 million people -- half the death toll of World War II -- would perish within the first week from blast effects, burns and acute radiation in India and Pakistan. This death toll would be 2,221 times the number of civilians and security forces killed by terrorists in India over nine years to 2015, according to an IndiaSpend analysis of South Asia Terrorism Portal data. Another two billion people worldwide would face risks of severe starvation due to the climatic effects of the nuclear-weapon use in the subcontinent, according to a 2013 assessment by the International Physicians for the Prevention of Nuclear War, a global federation of physicians.
The war heads
Pakistan has an estimated 110 to 130 nuclear warheads as of 2015 -- an increase from an estimated 90 to 110 warheads in 2011 -- according to a report from the Bulletin of the Atomic Scientists, a global disarmament advocacy. India is estimated to have 110 to 120 nuclear warheads.
Where Pak has placed its nuclear head
As many as 66 per cent of Pakistani nuclear warheads are mounted on 86 land-based ballistic missiles, according to Bulletin of the Atomic Scientists data estimates. Pakistan's Hatf series of ballistic missiles has been developed and is still under development keeping India in mind. A major attack by Pakistan's nuclear-tipped medium-range ballistic missiles (MRBMs) would likely target India's four major metropolitan cities New Delhi, Mumbai, Bengaluru and Chennai (depending on where the missile is fired from), according to Sameer Patil, fellow, national security, ethnic conflict and terrorism at Gateway House, a think tank in Mumbai. The MRBMs would also target "the major commands of the Indian Army," Patil told IndiaSpend.
Indian deployment
India has deployed 56 Prithvi (earth) and Agni (fire) series of surface-to-surface ballistic missiles, which carry 53 per cent of India's 106 estimated warheads, according to the Bulletin of Atomic Scientists. This doesn't take into account the estimated 12 warheads for the K-15 Sagarika submarine-launched ballistic missiles (SLBMs), which India has possibly produced for the nuclear-powered ballistic missile submarine INS Arihant. Once commissioned, Arihant would give India a strategic nuclear triad and second-strike capability. The 250 km-range Prithvi SRBM acts as a delivery system for 24 of India's warheads. These are capable of hitting major Pakistani cities, such as Lahore, Sialkot, the
capital Islamabad, and Rawalpindi, according to an IndiaSpend analysis. India has 20 nuclear-tipped Agni I SRBM and eight Agni II intermediate range ballistic missiles (IRBMs), with ranges of 700 km and 2,000 km, respectively. These are capable of covering almost all Pakistani cities, including Lahore, Islamabad, Rawalpindi, Multan, Peshawar, Karachi, Quetta and Gwadar. Agni III, IV and V, with their longer ranges, might be able to reach all of Pakistan, but it can be safely said that they are directed more towards China. India also possesses an estimated two ship-launched 350-km range Dhanush SRBMs, which could be fitted with nuclear warheads. India's aircraft can deliver an estimated 45 per cent of 106 warheads. The Indian Air Force's Jaguar fighter bombers can deliver about 16 nuclear warheads, while the French-built Mirage-2000 fleet can deliver 32.