In the unfolding scenario of the Third Nuclear Age, the world stands at the threshold of profound transformation, triggered by the changing landscape of military technology and the emergence of strategic non-nuclear weaponry (SNNW) as well as co-evolving nuclear threat perceptions. This pivotal juncture in history also sees the power disparity among nuclear-armed nations, namely the United States, Russia, China, and India, gradually diminish and the global dynamics fragment into regional nuclear dyads, thereby adding another layer of complexity to an already volatile geopolitical and security milieu.

The Ascendancy of Strategic Non-Nuclear Weaponry (SNNW)

This Third Nuclear Age is marked by a brisk rise in advanced non-nuclear military technologies including precision weapons, comprehensive missile defences, cyber technologies, and artificial intelligence (AI). Such weapons–especially adept as a counter-force arsenal–pose substantial challenges, effectively transforming the nuclear landscape and eroding deterrence architecture, mostly informed by frameworks latching onto the American-Soviet nuclear standoff as precedent. 

For example, with AI now incorporated into nuclear operations, weapon systems' precision, speed, and efficiency have significantly increased. This SNNW enhancement demands an immediate reassessment of nuclear doctrines and strategies. Within this context, Zala and Futter suggest four potential future trajectories centred around SNNW, each having distinct implications for global stability and nuclear crisis management.

1. The Arms Race Scenario: Here, the widespread deployment of SNNW triggers a new round of nuclear proliferation and intensifies arms races. This path leads to a perpetually evolving nuclear landscape due to the need for constant modernization and improvement of nuclear arsenals, bringing about increased tensions and posing significant challenges to crisis management and arms control. 

   High Likeliness: The Heritage Foundation contends that as China's military prowess grows, it necessitates the U.S. to have a robust nuclear force capable of convincingly conveying to China that the risks of nuclear warfare would significantly outweigh any potential gains. This statement underscores an increasing bipartisan urge for expanding procurement plans for current nuclear modernisation programmes. Meanwhile, the Stockholm International Peace Research Institute (SIPRI) estimated that as of January 2023, the global inventory of nuclear warheads totalled 12,512, with around 9,576 of these held in military stockpiles for possible use. This marks an increase of 86 warheads from January 2022. China's nuclear arsenal, in particular, has seen a steady uptick, rising from 350 warheads in January 2022 to 410 in January 2023. This escalating trend is expected to persist.

   This evolving scenario presents a dilemma. The shifting landscape of nuclear arms ownership and the worrisome rate of proliferation signal an escalating arms race that could substantially alter the world's geopolitical landscape. In the context of this, the strategic competition between the United States and China, wherein the U.S. views China as its main strategic rival, has set off an accelerating arms race in Asia, becoming a pivotal issue in global security.

   The rivalry between the U.S. and China not only intensifies the predicament but also heightens the risk of a major conflict brewing in the region. These military expansions are more than isolated contests; they form a complex network of interconnected rivalries that could potentially trigger a broad conflict.

   China's rapidly expanding nuclear capabilities have prompted India to speed up its nuclear program. This, in turn, has stimulated Pakistan to augment its weaponry. China is enhancing Pakistan's military capability to counterbalance India, while the U.S. amplifies its arms sales to India to curb China's rising influence, thus fuelling the regional arms race further. It is clear that these dynamics are not isolated, bilateral rivalries but are interlinked, potentially sparking a wider conflict. Thus, they underscore the urgency of international attention and action to prevent a catastrophic escalation.

2. The Strategic Advantage Scenario: In this outcome, a single nation achieves a dominant position in SNNW in terms of both quality and quantity. This disrupts the secure second-strike capabilities of rival nations, instigating a change in the strategies for managing nuclear crises and potential escalations. The implementation of SNNW establishes a significant advantage over traditional nuclear weapons, although it doesn't necessarily render them obsolete as power instruments. This dynamic, however, breeds instability, as it intensifies the entanglement between the nuclear and non-nuclear realms, making nuclear stockpiles susceptible. As a result, there is an escalation of tension that leans towards aggressive posturing as a means of deterrence amidst this vulnerability. 

   Moderate-High Likeliness:  A deeply isolated state with a turbulent relationship with the international community, North Korea faces an extraordinary level of perceived vulnerability. This perception stems from both internal factors—like the country's faltering economy and the fragility of its political structure—and external factors—such as the heaps of crippling international sanctions and geopolitical pressures. Thus, examining the Strategic Advantage Scenario further could benefit from delving into North Korea's past nuclear exploits to get a grip on the connection between perceived vulnerability and brinkmanship. 

   Perceived vulnerability, stemming from internal factors such as its faltering economy and fragile political structure, as well as external pressures such as stringent international sanctions and geopolitical stress, has placed North Korea in a position of severe isolation. This perceived vulnerability often fuels the nation's aggressive actions, prominently represented by its pursuit and development of nuclear weaponry and frequent missile testing. Throughout 2022, North Korea engaged in numerous assertive displays, launching 65 ballistic missile tests, including eight intercontinental ballistic missiles. North Korea's leader, Kim Jong Un, seems undeterred from surrendering the military initiatives deemed crucial for his regime's survival, indicating that, unless a strategic shift occurs, Pyongyang will continue its chosen path in the years to come.

   North Korea's defence agenda currently focuses on the development of a large range of  tactical nuclear weapons. Successful creation and deployment of these weapons would significantly lower the threshold for nuclear warfare on the Korean Peninsula, exacerbating regional vulnerability to nuclear conflict. The nation's strategic pursuit of nuclear weapons and ballistic missile technology has been marked by calculated escalations that ignite international concerns and increase tensions to force negotiations where North Korea is aiming to gain foreign aid, sanctions relief, or security assurances. This cycle of provocation and negotiation enables North Korea to survive its strategic position. But at a high cost, as the fielding of these weapons might necessitate riskier nuclear command-and-control practices, introducing possibilities for unintentional or accidental nuclear engagement.

   At its core, North Korea's strategy involves brinkmanship–a willingness to teeter on the brink of war, unfazed by potential catastrophic consequences. This high-risk, high-reward tactic has come to symbolise the nation's foreign policy. From North Korea's perspective, this approach was indispensable, facilitating the growth of its nuclear program while intermittently gaining concessions from the international community to survive despite the (expected) barrage of sanctions. North Korea's nuclear program serves dual purposes in its security policy: deterring perceived threats and amplifying its global standing. Paradoxically, this program, while providing a semblance of a protective shield, enhances the nation's vulnerability due to consequential international isolation and punitive measures. This intricate interplay of vulnerability and aggression forms the crux of North Korea's nuclear policy, highlighting the country's challenging navigation through the global nuclear order.

3. The Controlled Restraint Scenario: This trajectory sees nations exercising restraint in their development and use of SNNW, aided by arms control and normative frameworks. The focus is primarily on reducing nuclear risks and advancing disarmament. This path attempts to counter the destabilising effects of SNNW, thus retaining nuclear weapons as the primary instrument of power in international politics. 

   Low-Moderate Likeliness: Viewed from the standpoint of a Nuclear Weapons State (NWS), the Controlled Restraint Scenario is strategically appealing as it offers a way to sustain the current international power structure while simultaneously curtailing the global influence of Strategic Non-Nuclear Weapons (SNNW). This approach stresses the role of nuclear weapons as the primary lever of power in world politics, thereby potentially safeguarding the sway of nuclear-armed states, rather than advancing nuclear disarmament.

   The NWS's endorsement of this scenario is motivated by an intent to maintain the power equilibrium between nuclear "haves"—those with nuclear weapons—and "have-nots"—those without. Mexico's UN representative poignantly conveyed this dichotomy in 2022, stating that the 184 non-nuclear-weapon states fulfil their obligations under international non-proliferation and disarmament agreements on a daily basis, yet receive no tangible benefits in return. Rather dishearteningly, they endure a perpetual threat of annihilation by nuclear weapons, despite their commitment to non-proliferation principles.

   Furthermore, in the same context, Indonesia's representative drew attention to the lingering challenge of nuclear disarmament, castigating the NWS for their apparent reluctance to commit to the process. The representative underscored that these states often rationalise retaining nuclear stockpiles as a necessary measure for ensuring international security, which underscores the realpolitik approach of the NWS. The tension surrounding this issue has only been heightened by recent moves like the Russian Federation's plan to deploy non-strategic nuclear weapons in Belarus.

   In light of these circumstances, the Controlled Restraint Scenario is emerging as a potential strategy for the NWS to retain command over the evolving global nuclear narrative and maintain their dominance in the international system. This method aligns with their strategic interests as it enables them to curb the spread and influence of SNNW while preserving their nuclear weapons stockpiles, thereby supporting the power dynamics underpinned by these weapons.

   However, the successful execution of the Controlled Restraint Scenario requires substantial diplomatic outreach, mutual trust, and collaboration among nations—particularly between the NWS and Non-Nuclear Weapons States (NNWS). This shift would necessitate a reorientation of the current global order, moving from a framework of domination to one of shared responsibility. It would involve a leap of faith by NNWS, trusting that they will be duly compensated for not enhancing or even dismantling their SNNW capabilities.

4. The Non-Nuclear Stability Scenario: The final potential outcome foresees the proliferation of SNNW rendering nuclear weapons and secure second-strike capabilities obsolete. In this scenario, non-nuclear forces reach a state of equilibrium, creating stability rooted in deterrence by non-nuclear denial. This path could potentially lead to a world where nuclear disarmament is driven by technological advancements.

   Low-Moderate Likeliness: The steadfast trend of nations to augment and diversify their nuclear arsenals–with the remarkable exception of South Africa, who built and then dismantled their nuclear arsenal–forms one of the primary impediments to the realisation of the Non-Nuclear Stability Scenario. The global inclination towards nuclear armament reaffirms the enduring strategic value of nuclear weaponry, thereby casting a shadow over the potential predominance of strategic non-nuclear weaponry (SNNW) despite their advancements.

   The technological revolution in the military sector further dials down the probability of a transition to a non-nuclear world. As artificial intelligence becomes also an integral component of nuclear operations, the strategic worth of nuclear capabilities is rather amplified. The resultant enhancement of weapon systems' precision, speed, and efficiency underscores a transformation within the nuclear domain that could inhibit the shift towards SNNW dominance.

   The non-resolution and fluctuating nature of global arms control negotiations accentuate the moderately low probability of this scenario's manifestation. The ambiguity and stagnation that characterise these negotiations suggest an international reluctance to abandon nuclear weaponry despite the accompanying high risks. As a result, the potential for nuclear capabilities to maintain their stranglehold over strategic weaponry persists, thus potentially hindering SNNW's ascendancy. While it's plausible that accelerated technological innovations could outstrip nuclear policymaking and surpass the strategic rivalry, this dynamic primarily heightens nuclear risks rather than establishing the immediate superiority of SNNW and subsequent hard-earned stability through collective effort.

   Despite these inhibiting factors, catalysts exist that could potentially steer the world towards the Non-Nuclear Stability Scenario. The escalating global discourse on the urgency of nuclear disarmament could spark a shift towards a global aspiration for non-nuclear stability. Technological innovations that bolster crisis stability, particularly those that improve the accuracy and timeliness of intelligence acquisition, combined with growing international pressure to abolish nuclear weapons, could expedite the transition towards a non-nuclear equilibrium.

   Nevertheless, these changes concurrently introduce new risks such as unintended escalation, miscalculation, and potential nuclear use as the nuclear and non-nuclear domains continue to be deeply intertwined. Therefore, it's crucial to explore an array of future scenarios rooted in the ongoing evolution of current trends. We must acknowledge that we are dealing with what Lieber and Press describe as a "new era of counterforce."

   We are transitioning into a phase of having to carve out strategic stability from a nuclear order brimming with both nuclear and non-nuclear challenges, regardless which capabilities finally supersede. Weeding out the nuclear part of the equation and consequently forging a durable balance among SNNWs is no doubt a highly complex task.

The Reconfiguration of Strategic Stability

Historically, strategic stability has been firmly anchored onto nuclear weaponry. However, this established paradigm faces upheaval due to the advent of SNNW and shifting perceptions as well as entangled nature of nuclear threats.

The perceived value of nuclear weapons as a coercive “magic wand” in international politics is now being reassessed, with some experts arguing their primary utility is in defensive deterrence. The correlation between nuclear weapons acquisition and geopolitical influence no longer holds true, as exemplified by North Korea. Despite enduring sanctions and isolation, North Korea's acquisition of nuclear weapons has not resulted in substantial global influence.

Current mechanisms, normative frameworks, and agreements are ill-suited to address the challenges posed by SNNW. The potential for fostering stability through mutual vulnerability, adept crisis management, and addressing the linkages between SNNW and nuclear weapons remains underexplored. This new era requires a departure from the fixed mindsets, and a return to novel, critical thinking to cut through the fog. Meaning, key technological developments in the Third Nuclear Age, such as the advancement of comprehensive missile defence systems, proliferation of non-nuclear weapons, surge in cyber warfare capabilities, and integration of AI in military operations, are collectively reshaping nuclear dynamics. As the lines between offence and defence blur and the nuclear and non-nuclear spheres entangle,  a complex and quite likely perilous nuclear order emerges.

Global Security Implications and Future Challenges

Promoting stability in the Third Nuclear Age seems  feasible, yet daunting, requiring robust political planning and decisive action. The seismic shift in technology and evolving nuclear threat perceptions inherent to the Third Nuclear Age carry profound and novel implications for global security. Nations may increasingly rely on the development and deployment of SNNW to bolster their national security and global standing, potentially intensifying arms races and destabilising existing power balances.

The global security ramifications, including the increased risk of nuclear warfare and the undermining of nuclear non-proliferation treaties, are substantial and warrant urgent attention. Key policy recommendations should encompass fostering international dialogue on nuclear stability and promoting research and transparency in the development and deployment of SNNW. 

However, issues such as the defiance of states like North Korea and Iran, the ongoing conflict between India and Pakistan, and the disintegration of Russo-American nuclear arms control  present significant hurdles to nuclear stability. North Korea's refusal to surrender its nuclear program and Iran's potential infractions of the JCPOA complicate diplomatic negotiations. Both nations have consistently displayed a pattern of resistance to international pressure, leading to a myriad of unfulfilled commitments. The volatile relations between nuclear-armed nations Pakistan and India further impede progress, as recurring border disputes and a history of military confrontations often overshadow dialogue on nuclear stability. Compounding these challenges is Russia's recent departure from the New START, a once key pillar of nuclear arms control. This withdrawal threatens to erode mutual trust and oversight between the world's major nuclear powers, hindering constructive discussions.

These significant hurdles illuminate the complex task of fostering dialogue on nuclear stability and transparent SNNW development. As we venture further into the Third Nuclear Age, evolving nuclear threats essentially calls for a redefinition of our conception of global security, leaving many known frameworks behind. Recognizing these novel dynamics, integrating them into policy debates and forging new frameworks is not merely essential—it is vital for international stability.