It has been 22 years since India and Pakistan conducted their first nuclear weapons tests, igniting one of the worlds’ most dynamic nuclear deterrence relationships. The series of tests that were conducted at the turn of the century marked the beginning of an unconventional security competition between India and Pakistan which continues till today. Over the past two decades, a troubled past, domestic aspirations, alliances, and a trust deficit often fuelled competition between the two. In due course, significant shifts have occurred in terms of threat perception, deterrence, doctrine and strategy. Steady increases in the number of nuclear warheads, diversified delivery platforms and broadened fissile material infrastructure exhibit the changing trajectory of the last 22 years. While Pakistan depends on nuclear weapons now more than ever, India continues to modernize and expand its nuclear and conventional capabilities at a modest rate. China has influenced South Asia’s nuclear dynamics as well. Aggressive Chinese military posture against India and a history of Chinese assistance to Pakistan’s nuclear program has impacted India’s evolving nuclear capabilities. India’s concern lies in maintaining a modest nuclear arsenal which is capable of deterring China and Pakistan. Chinese investment initiatives, like the China-Pakistan Economic Corridor (CPEC), raise doubts about its geopolitical intentions in the region. South Asia faces a ‘nuclear trilemma’ due to China’s geopolitical aspirations in the region and beyond. While China may not consider India as a nuclear rival, India confronts challenges from two fronts that converge geopolitically into one at many levels. With India-Pakistan nuclear competition has its roots in conventional rivalry, there are practically no bilateral convictions for non use of nuclear weapons between the two. A trust deficit and frequent border skirmishes have risks of uncontrolled escalation with no established mechanism to deescalate the situation. This poses a greater challenge to the stability in South Asia. Although not much appears to happen behind the veil of secrecy on a daily basis in nuclear South Asia, the bigger picture suggests that nuclear dynamics of both India and have evolved drastically over the years. This article intends to evaluate several small and large changes undertaken by the two nuclear states since their evolution over three broad categories: (1) nuclear threat perception; (2) doctrinal shifts; (3) evolution of force capabilities and ending with the conclusion suggesting the importance of instituting dialogues and Confidence Building Measures (CBM) between the nuclear powers including China Threat Perception The bilateral relations between India and Pakistan have undergone a tumultuous path including three wars. A large part of Pakistan’s nuclear threat perception remains rooted in its history of conventional rivalry with India. The 1971 war of East Pakistan and the Kargil war of 1998 had dramatic setbacks for Pakistan. The two wars led to territorial loss and exposed conventional inferiority of forces vis-a-vis India. This had a profound impact on Pakistan’s overall military strategy as well as nuclear threat perception. Over the years, investments, reliance and centrality of nuclear forces have significantly increased. Pakistan has opted for nuclear asymmetrical response such as non-strategic nuclear weapons or Tactical Nuclear Weapons (TNWs), for example the Nasr, as an answer to India’s conventionally superior force. For India, the threat emanates from two fronts — Pakistan and China. The 1962 war fought against China came as a brutal lesson to India — a lesson that China cannot be a reliable partner. Further, the Chinese assistance to Pakistan in the mid 80s for the development of nuclear weapons cleared the path for India to continue the development of its own nuclear force. Apart from being regional rivals individually and having fought wars against both, China-Pak bonhomie has grown over the recent years and has occupied a place in India’s nuclear threat perception. The nuclear nexus between Pakistan-China and looming threat of two-front aggression worries India. However, China doesn’t currently see India as a major nuclear threat but continues to aid Pakistan as an all weather ally. Doctrinal Shifts Early phases of India and Pakistan’s nuclear doctrine evolved from their respective perceived threats. While Pakistan’s doctrine remained India centric, India’s nuclear doctrine had concerns over China and Pakistan. Initially, both India and Pakistan maintained a ‘Credible Minimum Deterrence (CMD)’. However, soon after the Kargil Conflict, as the conventional gap between the two armed forces became clear, Pakistan began to shift away from CMD. The gap between the two conventional forces impacted Pakistan’s nuclear thinking, its threat perception as well as its basic understanding of nuclear war fighting. India developed a ‘Cold Start Doctrine’ (CSD) in 2004. India’s CSD envisaged rapid deployment of troops consisting of Integrated Battle Groups (IBGs). Unsure of its tactical capabilities due to the existence of conventional gaps, Pakistan adopted ‘Full Spectrum Deterrence’ (FSD) in response. The FSD espoused the introduction of nuclear weapons in all spectrum of war fighting be it tactical, operational and strategic. It effectively blurred the distinction between conventional and unconventional war fighting by the introduction of Tactical Nuclear Weapons (TNW) which lowered the nuclear threshold. Today, nuclear weapons occupy prominence in Pakistan’s national security. Even more than conventional capabilities. Initially, India intended to pursue a policy of ‘credible minimum deterrence, as illustrated in the examples below. Two documents, one in 1999 under its National Security Advisory Board (NSAB) and the other in 2003 by the Ministry of External Affairs (MEA) essentially highlighted aspects of India’s nuclear doctrine. The two documents called for maintaining a credible and survivable nuclear force. Additionally, it also highlighted the centrality of No-First-Use (NFU) of Nuclear Weapons against Nuclear Weapons State and no use of nuclear weapons against a non-nuclear state except in case of a Chemical-Biological Weapons (CBW) use against India or Indian Armed Forces. Although no formal changes took place in the current doctrine since 2003, calls for a reassessment of India’s nuclear doctrine especially the efficacy of NFU has taken place in some political and military circles especially after the introduction of TNWs by Pakistan. Reports by some analysts suggest that the change in India’s NFU commitment is already taking place given India’s expanding capabilities. In a paper published in International Security Journal, Vipin Narang, a professor at the Massachusetts Institute of Technology and Christopher Clary, who teaches at the University at Albany, argue that India may give up its commitment to NFU citing new developments as offensive. Government of India’s official stand tends to differ with this speculation. It officially reiterated its commitment to NFU in the lower house of the Parliament. Nuclear Forces Capabilities Development of nuclear forces capability vis-á-vis land, air and sea has been rapidly evolving with more accuracy, variety of delivery platforms and expansive fissile material infrastructure in the region. India and Pakistan have around 140-160 warheads individually. However, the pace of Pakistan’s nuclear weapons program remains ahead of that of India. Estimates suggest that Pakistan has the fastest growing nuclear program and will be the third largest nuclear weapons state by 2025. While India emphasizes development and modernization of its newly developed nuclear triad, Pakistan nuclear force development includes non-strategic weapons , sea-based cruise missiles, air launched cruise missiles, and longer-range ballistic missiles. Expanding into the sea, India functionally operates its sea based nuclear deterrent in the Indian Ocean Region (IOR). Pakistan too established its Pakistan’s Naval Strategic Force Command in 2012 in quest for a second strike capability. Of note that China plays a crucial role in development of Pakistan’s sea based deterrence by providing technical assistance as well as procurement of dual use submarine technology. Air-leg of India’s nuclear strike capabilities include active air squadrons consisting of upgraded Mirage 2000H and Jaguar IS aircraft. India’s recent induction of Rafale aircrafts procured from France is speculated to take over the older bomber aircrafts. India’s land based ballistic missiles comprises of Short Range Ballistic Missiles (SRBM’s) like Prithvi-II and Agni-I, Medium Range Ballistic Missile (MRBM’s) like Agni-2 and Agni-3, Agni-4 and Agni-5 as Intermediate Range Ballistic Missile (IRBM’s). While not all of them are fully inducted, the IRBM will have capacity to reach all major cities of China and Pakistan. Sea based ballistic missile includes Dhanush which is nuclear armed and is of short range. Others include K-15 and K-4 which are yet to be fully inducted. Pakistan’s land based ballistic missiles comprises SRBM like Hatf-2, MRBM like Shaheen-II and Ababeel capable of delivering multiple warheads through Multiple Independent Re-entry Vehicle (MIRV). In the naval front, it has Babur-I, Babur-2, Ra’ad and Ra’ad-2 as Ground and Air Launched Cruise Missile (GLCM). Babur-3 is a Sea based Cruise Missile (SLCM). Apart from a wide range of ballistic missiles, Pakistan has very short range TNWs. A wide range of ballistic missiles/delivery platform emphasises the doctrinal change from ‘Credible Minimum Deterrence’ to ‘Full Spectrum Deterrence’. When it comes to nuclear stockpiles, Both India and Pakistan have active fissile material infrastructure, capable enough of producing weapon grade material. Most of India’s nuclear reactors are meant for civilian purposes and are safeguarded. Pakistan’s majority of nuclear infrastructure is dedicated for military purposes and has relatively very less amount of stockpiles safeguarded for civilian use. Conclusion Nuclear policy developments over two decades have completely changed security dynamics in South Asia. Most of these changes are a consequence of conventional power disparities and trust deficits between India, Pakistan and China. China plays a predominant role in South Asian nuclear dynamics. China’s conventional power disparity has led two unique outcomes. Both India and Pakistan seek to match the existing disparity against China and India consecutively. While India has maintained a modest balance between its conventional and nuclear power in terms of development, Pakistan has relied more on non-conventional and asymmetric strategies for deterrence. With no working mechanism for de-escalation, competence and over-emphasis on nuclear weapons has effectively lowered the nuclear threshold precariously endangering stability in times to come. This is evidenced by doctrinal and force structure changes over the last 22 years. South Asia desperately needs more dialogues between the nuclear nations including China to reinstate mechanisms for communication and Confidence Building Measures. While deterrence may prevent a nuclear catastrophe, deterrence without dialogue always runs the risk of an unintentional nuclear war.  Although India conducted its first nuclear tests in 1974 (Smiling Buddha), the tests were largely a demonstration of nuclear capabilities. In 1998, the Government of India officially declared its nuclear weapons capabilities.