Pakistan's nuclear thinking, its ambiguous doctrine, and posture-revolving around the much-acclaimed fill spectrum deterrence, remains critical for Indian policymakers and the international security community. The Pakistani security rationale is indeed one of the crucial dimensions of Pakistan's complex dynamics. In this context, the narrative of Pakistan's threat perceptions becomes an integral part of its strategic posturing for both the outside world and domestically, to justify its inclination (and excessive diversion of national resources) towards defence and nuclear build-up. With all the existing domestic, economic, and security challenges, which are detrimental to nation's growth, the stable factor has been Pakistan's military and nuclear build-up. Past experience suggests its acquisition of nuclear weapons and expansion of the arsenal will continue to be rationalised as an ultimate guarantee of security, deterrent to Indian conventional military superiority, to perceived threat perceptions vis-à-vis India, and to provide an umbrella to pursue a proxy war through terrorism. In this context, it is important to undertake a study on Pakistan's security dimensions and its nuclear positioning to allow India to evaluate its options against Pakistan.