The Indo-Pak rivalry has been the most important security concern of the region. The hostile relationship between India and Pakistan have resulted in three full-scale wars, one undeclared conflict in Kargil and various limited conflagrations across the borders of two big neighbors in the region. The regional peace has been vulnerable due to incomplete partition plan followed by interstate disputes and the arms race.

The Indo-Pak relations and the strategic equation of the region have undergone a dramatic shift when India started its nuclear program. India conducted nuclear weapon tests in 1974 to counter perceived threats from China and Pakistan, and to extend its influence across the region. Acquisition of nuclear weapon by India created the security dilemma for South Asian countries, particularly for Pakistan. Consequently, Pakistan initiated its nuclear program for counterbalancing Indian conventional and greater nuclear capabilities. On 28 May 1998, Pakistan responded to a series of Indian nuclear tests and finally carried out a successful nuclear test in Chaghi. Pakistan termed its tests essential for credible nuclear deterrence, essential for peace and stability of the region. The acquisition of nuclear weapons and the employment of nuclear deterrence created a strategic space for Pakistan where chances of high-intensity conventional warfare by India were lowered.

The debate among strategic thinkers and scholars on nuclear deterrence of South Asia has created two camps where one favor the proliferation vis-à-vis deterrence theory while others negate the applicability of the same. Given the historical rivalry between India and Pakistan, proliferation optimists argue South Asia has become a successful case of nuclear deterrence. It is argued that prior to nuclear tests of 1998 India and Pakistan had three declared wars (1948, 1965 and 1971). However, after these tests, the military crisis of 1999 limited war in the Kargil and 2001–02 mobilization of million troops on their borders did not escalate into larger conflicts. In both of these military crises, optimists argue that nuclear deterrence kept peace in South Asia. Based on this, optimists maintain that the South Asian case provides one of the strongest pieces of evidence to support deterrence theory. Strategic thinkers like Kenneth Waltz also views South Asia as the decisive test for deterrence optimists and suggests that the nuclear deterrence has passed all of the many tests it has faced.

In the aftermath of Pulwama incident, the Indian aggression followed by Pakistan’s response was also regulated through nuclear deterrence. India’s attack on Balakot was driven by conventional means aimed to engage Pakistan in limited war. In turn, instead of going to full spectrum nuclear response, Pakistan acted rationally and relied on conventional means for defending its sovereignty. It was being widely argued that nuclear deterrence failed in post-Pulwama crisis. However, Dr. Rabia Akhtar contended this argument and said that the validity of deterrence will always remain intact until India captures Pakistani territory and does not get a response from Pakistan. Moreover, the nuclear capability of South Asian neighbors also compelled the international community to play their diffusing the tension.

Since 1999 till today the South Asian region has seen various military crisis between Pakistan and India. However, this crisis did not escalate to reach the full-scale war. It is believed by many that the balance of threat in the wake of a nuclear weapon has been instrumental for preventing escalation of such confrontations. Given the strategic importance of nuclear deterrence, south Asian security paradigms are molded in a way where chances of war and large-scale confrontation is considerably reduced. On various occasions, since the acquisition of nuclear weapons by Pakistan, nuclear deterrence has played a vital role in maintaining strategic stability and peace in the region.