Southeast Asia’s Nuclear Blind Spot: Latent Pathways and Explicit Pressures
A Chinese Jin-class nuclear submarine is seen in December 2010 | CRS / U.S. NAVY OFFICE OF LEGISLATIVE AFFAIRS
In an article for War on the Rocks, Hely Desai writes about why Southeast Asia is becoming more vulnerable to nuclear risk despite being formally non-nuclear.
Southeast Asia’s Nuclear Weapon-Free Zone has long been treated as a stabilizing firewall in an otherwise volatile region. Yet despite the continued legal compliance and strong anti-nuclear norms, the region is increasingly exposed to nuclear danger.
Across East Asia, nuclear dynamics are shifting in ways that extend beyond overt weaponization. The most consequential changes stem from the diffusion of nuclear-adjacent capabilities across maritime strategy, civilian nuclear development, and conventional military competition. Prevailing assessments have largely only focused on flashpoints in Northeast Asia — particularly the Korean Peninsula — where North Korea’s expanding “nuclear shield and sword,” advances in submarine-launched ballistic missiles, and China’s accelerating nuclear modernization alongside Beijing’s military pressures on Taiwan have intensified deterrence pressures on U.S. allies. Concerns over hedging in South Korea and Japan amid questions about extended deterrence credibility underscore this landscape. Recent maritime developments — including Pyongyang’s pursuit of a nuclear-powered, nuclear-armed submarine, Washington’s agreement to assist Seoul with nuclear-powered submarine development, and new permissions for uranium enrichment and spent fuel reprocessing — have only sharpened pre-existing proliferation anxieties. Yet these northern dynamics have increasingly radiated southward.
Southeast Asia, also in the crosshairs of intensifying U.S.-Chinese rivalry and contested maritime spaces, has now been facing growing exposure to nuclear-powered and potentially nuclear-armed naval assets. China’s reported submersible ballistic nuclear submarine deployments into the South China Sea, sustained U.S. naval presence and freedom of navigation operations, and expanding anti-submarine warfare activities, alongside a brewing missile race are gradually transforming the region into a theater of nuclear-adjacent competition. Even conventional incidents occurring in such a volatile region may therefore have the potential to draw in strategic assets, raising escalation risks and complicating the Association of Southeast Asian Nations’ efforts to preserve their autonomy and cohesion.
