This is the second part of a two-series commentary. Read part one here.
BY SYLVIA MISHRA
Strategic stability through three nuclear ages
First Nuclear Age
Overarching nuclear rivalry between the US sand the former Soviet Union defined it and the possibilities of nuclear weapons use deliberately, by accident or in an unauthorized manner were determined overwhelmingly by the actions of the US and Soviet Union. The first nuclear age was shaped by a nuclear arms race, global ideological competition and elements of cooperation between two superpowers.
Strategic stability in this first nuclear age was marked by the logic of mutually assured destruction (MAD), a concept pushing both the US and Soviet Union to exercise restraint and prevent a nuclear conflict — whoever shoots first dies second. Both superpowers bilaterally agreed on several arms control agreements and advanced nuclear crisis management efforts and settled on a mutual understanding of nuclear force postures and capabilities that maintained strategic stability. While there was no overt military confrontation, the adversaries had several close calls, fought proxy wars and pursued arms races.
In the post-Cold War period, Russia lost much of the economic, technological, and political strength of the Soviet period, but remains a nuclear superpower and preserves its great power aspirations. Dmitri Trenin, director of the Carnegie Moscow Center posits that Russia faces an asymmetrical balance of power in its confrontation with the United States and resorts to nuclear parity as a key component of its leverage with Washington. It is not surprising that there is an erosion of bilateral strategic relations between the UA and Russia given the vast differences in economic, political and technological power. And while there is strategic stability at the apex, economic factors, budgetary constraints, and technological advancements are chipping at the former foundation of US-Russia strategic stability. 
Second Nuclear Age
The end of the Cold War and the fall of the Berlin Wall ended the First Nuclear Age. The emergence of new nuclear-armed countries on the horizon paved the way for a second nuclear age and multipolar competition with the capability of disrupting strategic stability. Yet efforts have been made to sustain global strategic stability by engaging in bilateral and multilateral discussions, arms control and non-proliferation efforts and resorting to diplomacy and confidence-building measures. As the locus of the Cold War shifted from Europe to Asia, the nuclear policy landscape has become more complex.
While the US and Russia’s nuclear weapons inventories and stockpiles have been reduced, China, India, Pakistan, and North Korea are bolstering and expanding their nuclear arsenals. Israel too possesses a considerable number of nuclear weapons but has remained ambiguous about its status as a nuclear-armed state. While the first nuclear age was shaped by nuclear rivalry between the US and the Soviet Union, the second nuclear age is defined by the multiplicity of nuclear powers linked by various levels of cooperation and conflict.
In a Council on Foreign Relations report, Gregory D. Koblentz found strategic stability faced three challenges: first, the increasing complexities of deterrence relations, and the rise of a security trilemma – defensive actions taken by a state against another having the effect of making a third state feel insecure; second, the emergence of nonnuclear military technologies with the potential to replicate, offset and mitigate the strategic effects of nuclear weapons; and third, the risk of a breakdown of strategic stability in South Asia due to several factors of unresolved territorial disputes, cross border terrorism and expanding nuclear arsenals.
Some of the key trends of the second nuclear age challenging strategic stability issues are – multiple nuclear-armed states are at different stages of nuclear weapons developments; North Korea, India, and Pakistan are trying to build second strike capabilities and also undergoing changes in their force structures, and doctrines.
Amid changes in the strategic environment, few observers have pointed out that Pakistan’s doctrinal thinking is undergoing a shift from establishing ‘existential deterrence’ to a ‘complex deterrence posture’ of maintaining a strategic balance. Though the idea of changes in India’s nuclear doctrine is intensely debated, nevertheless, scholars have raised the issue whether India is shifting to a nuclear counterforce strategy and what changes in the nuclear doctrine it might entail. Geopolitical rivalries are once again coming into sharper focus and seemingly the global nuclear order will undergo significant changes as regional conflicts will possibly be marked by nuclear-tinged crises such as the Pulwama-Balakot crisis between India and Pakistan (February-March, 2019) and also might run the risks of inadvertent escalations. Additionally, waning arms control and disarmament efforts have also given impetus to nuclear-armed countries to embark on massive nuclear modernization and expansion efforts. In the second nuclear age, given China’s continuing development of its strategic capabilities, especially anti-satellite and offensive cyber weapons, the US needs to establish strategic stability with China through a mix of deterrence strategies and bilateral dialogues.
The Third Nuclear Age
In the 21st century the rapid pace of development of science and technology has established a new era in the strategic landscape. Multipolar competition coupled with a renewed arms race of emerging technologies that challenges the existing deterrence paradigm has produced a significant shift in how strategic stability was traditionally sustained and maintained.
Development of destabilizing technologies and the blurring of lines between nuclear and non-nuclear forces will markedly change the strategic landscape in future. Jenny L. Naylor in her paper, ‘The Third Nuclear Age,’ argues that while the arms race during the second nuclear age was primarily concerned with the quantity of strategic nuclear stockpiles, the third nuclear age will be marked by a race to develop game changing, dual-capable weapons and to innovatively apply technologies on the battlefield.
The US, China, and Russia are largely pursuing similar military technologies and Chinese investments in emerging technologies development demonstrates that it is intent on achieving peer-competitor status with Russia and the US through its scientific and technological prowess. China’s focused R&D investments in dual-capable technologies, hypersonic and underwater drones for example, that could defeat early warning and antiballistic missile defense and challenge U.S. nuclear command, control, and communication (NC3), is evidence
In the third nuclear age, there are several challenges to maintaining strategic stability, such as the abandonment of the principle of mutual vulnerability which served as the corner stone of stable nuclear-armed relationships. Nuclear and non-nuclear has also become entangled resulting in difficulties distinguishing between strategic and non-nuclear weapons. This idea of integration/commingling of nuclear and non-nuclear forces or as scholar James Acton puts it “entanglement” and its impact on doctrinal and operational readiness of nuclear and non-nuclear forces and support structures is potentially going to have significant impact in deterrent relationships.
This new nuclear age is pushing strategic thinkers to rethink deterrence strategies, issues of global governance of nuclear nonproliferation and arms control, to maintain strategic stability. Some of the defining features and trends of the third nuclear age will be that geopolitical rivalry will determine, impact and guide nuclear armed countries nuclear force structures, deployments, and postures. While arms control efforts are steadily on the decline, it must be noted that emerging technologies and their use will precipitate the need for governance and crisis management.
The geopolitical, technological, and psychological landscape that helped prevent war between the world’s nuclear powers, and the concept of strategic stability and conditions for maintaining strategic stability, have fundamentally changed. In the evolving third nuclear age where deterrence relationships are complex, and there is a growing entanglement of nuclear and non-nuclear weapons, it behooves the US to take the lead on establishing strategic stability.
US policymakers need to appreciate that the conditions and instruments for managing nuclear crises and preventing a nuclear conflict have significantly changed.
To maintain, sustain and even strengthen, strategic stability under these increasingly complex and rapidly changing conditions needs rethinking of long-standing notions and policies promoting strategic stability adjusted to meet the challenges of the twenty-first century.
While the importance of the US and Russia resuming bilateral strategic stability discussions has drawn attention, of critical importance is also the need for further examination of the differences in perception of strategic stability between US-Russia and US-China. As the nuclear order is undergoing changes, it is in US national security interests to ensure that nuclear-armed countries are engaged in constructive bilateral and multilateral dialogues for identifying and addressing sources of instability and the ways to best address them through clear communications and credible deterrence strategies.
 Dmitri Trenin, ‘Strategic Stability in the Changing World’, Carnegie Moscow Center, March 21, 2019, available at carnegie.ru/2019/03/21/strategic-stability-in-changing-world-pub-78650
 “Israel Reasserts Nuclear Ambiguity”, Nuclear Threat Initiative, December 13, 2006, available at www.nti.org/gsn/article/israel-reasserts-nuclear-ambiguity/
 Gregory D. Koblentz, ‘Strategic Stability in the Second Nuclear Age’, Council on Foreign Relations, 2013.
 Sadia Tasleem, “Pakistan’s Nuclear Use Doctrine” Carnegie Endowment for International Peace, June 30, 2016, available at https://carnegieendowment.org/2016/06/30/pakistan-s-nuclear-use-doctrine-pub-63913
 Christopher Clary and Vipin Narang, “India’s Counterforce Temptations: Strategic Dilemmas, Doctrine, and Capabilities.”, International Security, Vol. 45, Issue 3, February 15, 2019, available at www.mitpressjournals.org/doi/full/10.1162/isec_a_00340
 Toby Dalton, “Signaling and Catalysis in Future Nuclear Crises in South Asia: Two Questions after the Balakot Episode”, Carnegie Endowment for International Peace, June 25, 2019, available at https://carnegieendowment.org/2019/06/25/signaling-and-catalysis-in-future-nuclear-crises-in-south-asia-two-questions-after-balakot-episode-pub-79373. The article was originally published by the Nuclear Crisis Group, available at www.globalzero.org/wp-content/uploads/2019/06/South-Asia-Post-Crisis-Brief.pdf
 Ankit Panda, “U.S. Nuclear Weapons Modernization”, Council on Foreign Relations, February 7, 2018, available at www.cfr.org/backgrounder/us-nuclear-weapons-modernization
 Frank A. Rose, ‘Bringing China into the Fold of Arms Control and Strategic Stability Issues’, Brookings, September 25, 2019, available at www.brookings.edu/blog/order-from-chaos/2019/09/25/bringing-china-into-the-fold-on-arms-control-and-strategic-stability-issues/
 Jenny L. Naylor, “The Third Nuclear Age”, Comparative Strategy, 38:4, 276-288, DOI: 10.1080/01495933.2019.1633185 , available at www.tandfonline.com/doi/pdf/10.1080/01495933.2019.1633185?needAccess=true
 Jenny Naylor, Ibid.
 Maria Rost Rublee, “Nuclear Deterrence Destablized”, in Perspectives on Nuclear Deterrence in the 21st Century, (Chatham House, April 2020)
 James M. Acton, “Entanglement: Russian and Chinese Perspectives on Non-Nuclear Weapons and Nuclear Risks”, (Carnegie Endowment for International Peace, 2017).
 “Russia, US Agree to Meeting of Experts on Military Doctrines”, TASS Russian News Agency, June 25, 2020, available at https://tass.com/politics/1171747