Deciphering Strategic Stability in the Age of Speed: Hypersonic Weapons in South Asia

In South Asia, India is pursuing an ambitious program to develop Hypersonic Boost-Glide Vehicles (HBGVs) and Hypersonic Cruise Missiles (HCMs). This paper examines India’s hypersonic program and analyzes how these weapons may reshape the strategic stability in South Asia. It argues that India’s development of hypersonic weapons is unlikely to upend the regional strategic equilibrium. Nevertheless, hypersonic weapons are likely to accelerate India’s strategic build-up, thereby undermining strategic stability in South Asia. During a limited military conflict with Pakistan, India would have strong incentives to use hypersonic weapons for “Destruction of Enemy Air Defenses” (DEAD) missions and to strike Pakistan’s air bases, conventional missile storage sites, and launch platforms. This would heighten crisis instability by creating serious risks of conventional-nuclear entanglement and raising the risk of nuclear escalation. Furthermore, India’s hypersonic weapons would amplify its counterforce temptations by putting at risk land and air components of Pakistan’s nuclear triad, thus creating first-strike instability. Consequently, Pakistan would be compelled to undertake measures to augment the survivability of its nuclear arsenal, while India would be continuously seeking to gain the counterforce edge. The unremitting cycle of action and reaction would precipitate instability in the arms race in South Asia.