Asia's four regionalisms (Southeast Asia, South Asia, Central Asia and East Asia): a view from multilateral treaties of the United Nations

Asia is the largest and most diverse continent, marked by wide disparities in development and distinct historical trajectories toward sovereignty. Against a backdrop of post–World War II reconstruction, Cold War dynamics, and contemporary global challenges such as climate change and pandemics, the paper asks: (1) How quickly do Asian states participate in the United Nations’ multilateral treaties? and (2) How have Asian states adapted to these treaties over time? The motivation stems from the observed correlation between development performance and participation in multilateral treaties, coupled with a gap in quantitative, systematic analysis of Asian states’ ratification speed and temporal adaptation across policy areas. The study focuses on ratification as the pivotal formal act of commitment to treaty-based regimes and proposes a quantitative index—the Treaty Participation Index (TPI)—to capture states’ eagerness or caution in joining multilateral treaties across six domains: peace and disarmament; trade, commerce, and communication; intellectual property; human rights; environment; and labor and health. It further evaluates the feasibility and sustainability of four Asian regionalisms—East Asia, Southeast Asia, South Asia, and Central Asia—through comparative, evidence-based metrics within the UN treaty system.

A major precedent in the quantitative study of multilateral treaty-making is Denemark and Hoffmann’s Multilateral Agreements and Treaties Record Set (MATRS), a dataset of 7000 agreements from 1595–1995 categorized into six general issues (social affairs; war and peace; communication and transportation; environment; states and relations; trade and economy). Their work identified temporal, spatial, and issue-area patterns of treaty-making and diffusion globally. Van der Wusten and colleagues analyzed the geography of treaty-signing venues, showing continuity and functional-political drivers of venue selection. Glas and co-authors applied network theory to multilateral treaties to map inter-state ties and structural attributes, positioning states as nodes formed by shared treaty participation. While these works illuminate patterns of treaty creation and structural relations, the time dimension as a metric for states’ ratification speed remains underexplored. The present study extends this literature by focusing on ratification timing as an indicator of willingness and adaptability, providing a quantitative TPI to enable sub-regional and temporal comparisons within Asia and between Asia and the world.

Conceptualization: The study focuses on ratification as the formal act indicating a state’s commitment to treaty regimes. To capture ratification speed, for each treaty-country pair i, the delay D_i is defined as the elapsed years between treaty promulgation (Y_p) and ratification (Y_i): D_i = Y_i − Y_p. The Treaty Participation Index (TPI) is defined as TPI = 1 / (1 + D). Immediate ratification yields TPI = 1; non-participation yields TPI = 0. Dataset: The analysis covers 600 major multilateral treaties deposited within the UN system from 1945 to 2020, with ratification years recorded per state. Sources include: United Nations Treaty Collection (UNTC); WIPO-Administered Treaties; and ILO’s NORMLEX Information System on International Labour Standards. Treaties are classified into six policy domains, adapted from Koenig-Archibugi’s global governance map and Denemark & Hoffmann’s categories: environment (52), human rights (53), intellectual property (36), labor and health (110), peace and disarmament (84), trade, commerce, and communication (265). Units of analysis: Twenty-eight Asian countries are grouped into four sub-regions: East Asia (China, Japan, South Korea, North Korea); Southeast Asia (Philippines, Vietnam, Myanmar, Thailand, Cambodia, Laos, Malaysia, Brunei, Singapore, Indonesia); South Asia (India, Pakistan, Bangladesh, Nepal, Sri Lanka, Bhutan, Maldives, Afghanistan); Central Asia (Kazakhstan, Uzbekistan, Tajikistan, Kyrgyzstan, Turkmenistan, Mongolia). Analytical approach: TPI is computed per country-treaty and aggregated to produce domain-level and sub-region-level metrics. Comparative analyses include Asia vs. world averages by domain, and temporal comparisons across three periods: Cold War (1945–1989), post–Cold War (1990–2007), and a decade after the global recession (2008–2019). Figures and tables summarize average TPI values and distributions across domains, sub-regions, and time.

Cross-domain averages (Table 1): - Environment: World 0.215; Asia 0.212 - Human rights: World 0.170; Asia 0.197 - Intellectual property: World 0.120; Asia 0.118 - Labor and health: World 0.165; Asia 0.175 - Peace and disarmament: World 0.155; Asia 0.150 - Trade, commerce, and communication: World 0.225; Asia 0.245 Peace and disarmament: India is fastest in Asia (TPI = 0.16; ~5-year average delay), followed by the Philippines (0.14) and Japan (0.11). Many others show 10–50 year delays; Myanmar, Bhutan, and North Korea are slowest (TPI ≈ 0.02). Central Asia generally exhibits low TPI (0.03–0.07) with Mongolia higher at 0.08. East Asia shows strong intra-regional disparities (Japan fast; China and South Korea around 0.05; DPRK very low). Trade, commerce, and communication: Despite dynamic economies, participation is generally not rapid. Malaysia, Japan, and South Korea are relatively active yet below 0.1 TPI (~10-year delays). Many countries show 20–60 year delays. East Asian leaders (Japan, South Korea) near 0.08; China’s participation rises post-1970s; DPRK ~0.01. Central Asia is low (Kazakhstan ~0.02). Southeast Asia shows wide disparities (Malaysia, Thailand, Singapore higher; Laos, Myanmar near 0.02). South Asia: India leads (~0.07); Bangladesh and Sri Lanka ~0.04; Afghanistan and Nepal ~0.02. Intellectual property: Ratification is slow across Asia (10–50 year delays). Japan leads (TPI ~0.1). South Korea and China also ~0.1 with strengthened IP frameworks. Remarkably, DPRK reaches ~0.05 (highest DPRK TPI across domains), reflecting engagement with WIPO. South Asia: India near 0.1; Bangladesh and Sri Lanka 0.03–0.06; Afghanistan, Nepal, Maldives, Bhutan 0.01–0.02. Southeast and Central Asia mostly 0.03–0.07; enforcement challenges remain in some countries (e.g., Vietnam, Laos, Brunei; Tajikistan, Uzbekistan ~0.03). Human rights: Asian ratification delays typically 10–30 years. South Asia (India, Pakistan, Sri Lanka) shows highest activity (TPI 0.17–0.23; ~5-year delays). East Asia records gains, with China ~0.2; Japan comparatively slow (TPI ~0.04; ~20-year delay). Philippines (SEA) and Mongolia (Central Asia) around 0.1; Brunei and some Central Asian states (Tajikistan, Uzbekistan, Turkmenistan) low (0.01–0.03). Environment: This domain shows the fastest and most consistent participation across Asia (typical delays 5–15 years). East Asian leaders (Japan, South Korea, China) near 0.1 in figure-based depiction; overall Asia’s average is high (Asia 0.212 vs world 0.215). Strong regional commitment yet enforcement/implementation challenges persist. Labor and health: Asia is comparatively slow (10–50 year delays). India and China lead (TPI ~0.12). Central Asia is lowest (~0.02–0.04). East Asian market economies show relatively active roles (China, Japan, South Korea), excluding DPRK. Temporal adaptation: - Peace and disarmament: During the Cold War, South Asia’s TPI was well above the world average; post–Cold War, South Asia declined while East Asian participation (e.g., China, South Korea) rose. After 2008, all Asian sub-regions declined (Asia ~0.10 vs world ~0.14), indicating Asia is not assuming leadership in peace regimes. - Human rights: South and Southeast Asia exceeded the world average during the Cold War but converged to global averages thereafter. East Asia rose sharply post-2008, leading in rapid commitments during that decade. - Labor and health: East, Southeast, and South Asia were active early but declined steadily after 1989; Central Asia improved but overall Asian averages align closely with global levels. - Trade, commerce, and communication: Post–WWII expansion saw Asia (South, East, Southeast) above the world average; emerging economies (e.g., China, South Korea) became more active post–Cold War; Central Asia increased from a low base; South Asia showed a contrasting later trend. - Environment: Participation increased over time; excluding Central Asia, Asian sub-regions were more active than the world average in the post-2008 decade. - Intellectual property: Southeast and South Asia were active through the post–Cold War but dropped below the world average after 2008. East and Central Asia shifted upward markedly; East Asia’s TPI ~0.17 vs world ~0.09 post-2008.

The findings address the core questions by quantifying the speed of participation (TPI) and tracing adaptation over time. First, Asian states’ ratification speed varies widely by domain and sub-region: environment and trade/communication show relatively fast and broad engagement; peace/disarmament and intellectual property exhibit slower, more heterogeneous uptake. Second, temporal analyses reveal shifting leadership: South Asia led in peace/disarmament during the Cold War but receded thereafter, while East Asia accelerated in human rights and intellectual property post-2008. Asia as a whole tends to meet or exceed world averages in environment and trade/communication, yet lags in peace/disarmament in the recent decade. Regarding the feasibility of four Asian regionalisms, the TPI patterns indicate limited cohesive clustering except in Central Asia, where consistently modest scores across domains suggest passive and sparse participation. East Asia performs strongly in intellectual property, environment, and trade/communication but exhibits pronounced intra-regional disparities (Japan/South Korea vs DPRK). South Asia features a wide distribution: robust in human rights but weaker in labor/health; former British colonies (India, Pakistan, Sri Lanka) show higher engagement across several domains than Bhutan, Nepal, and Maldives. Southeast Asia’s diversity, ASEAN’s non-interference norm, and evolving ASEAN Centrality correlate with heterogeneous treaty participation. These dynamics support a nuanced view of regionalism in Asia: shared challenges and some domain leadership coexist with deep variation in willingness and speed to enter treaty regimes. The results are pertinent to debates on the shift from international to global politics, highlighting how multilateral treaties structure regional adaptation and cooperation.

The study develops and applies the Treaty Participation Index (TPI) to quantify Asian states’ engagement speed with UN multilateral treaties across six policy domains and three historical periods. Using a dataset of 600 UN-deposited treaties and 28 Asian countries grouped into four sub-regions, it provides comparative metrics within Asia and versus global averages. Key contributions include: (1) establishing a simple, transparent time-based index (TPI) of treaty participation; (2) documenting domain-specific and sub-regional differences in speed and adaptation over time; and (3) assessing the feasibility of four Asian regionalisms through evidence-based participation patterns. Central Asia emerges as a distinct, low-participation cluster; East Asia shows high engagement with internal disparities; South and Southeast Asia are heterogeneous with domain-specific strengths and weaknesses. Future research will apply quantitative clustering (e.g., k-means, hierarchical, density-based) to identify data-driven groupings of countries by treaty adoption profiles, and examine how regional cooperation mechanisms adapt to evolving global dynamics to inform scenarios for Asian regionalisms and broader regional integration.