Rank #13 · Asia-Pacific
South Korea spent $47.8B on its military in 2025, ranking 13th globally and devoting 2.6% of GDP to defence — almost entirely focused on deterring North Korean nuclear and missile threats while powering an export-driven defence industrial boom led by Hanwha, KAI, and Hyundai Rotem.
The Ministry of National Defense FY2026 budget (KRW 66.3 trillion, approximately $48-50B) maintains the 4.5%+ year-on-year growth trajectory set by the 2024-2028 Mid-Term Defense Plan. The plan allocates roughly KRW 348 trillion over five years, with about a third earmarked for force-improvement (procurement and R&D). Priority programs include the Korea Air and Missile Defense (KAMD) layered system, the Strategic Strike System (Kill Chain), the Korea Massive Punishment and Retaliation (KMPR) capability, and the indigenous KF-21 Boramae fighter. R&D spending alone reached over KRW 5 trillion in 2025, the highest absolute and relative share among major Asian spenders.
The Republic of Korea Armed Forces field roughly 500,000 active personnel — Army ~365,000, Navy ~70,000 (including 29,000 ROK Marines), and Air Force ~65,000 — alongside a mobilization base of around 3.1 million reservists. The Army operates K2 Black Panther tanks, K9 Thunder self-propelled howitzers, and a deepening Hyunmoo ballistic and cruise missile arsenal underpinning the three-axis deterrence concept. The Navy fields three Sejong the Great-class Aegis destroyers (with three additional Batch-II Aegis hulls under construction), Dosan Ahn Changho-class submarines, and a planned light aircraft carrier. The Air Force operates F-35As, F-15Ks, KF-16s, and accepted the first KF-21 Block 1 deliveries in 2026.
South Korea has emerged as a top-10 global arms exporter, with Hanwha Aerospace, KAI, LIG Nex1, Hyundai Rotem, and HD Hyundai Heavy Industries dominating output. The 2022-2024 Polish package — K2 tanks, K9 howitzers, FA-50 light combat aircraft, and Chunmoo MLRS — totalled tens of billions of dollars and remained the headline export contract through 2025. Additional 2025 deals included Romanian K9s, Egyptian K9s, and a Polish K2PL co-production framework. The KF-21 entered low-rate production in 2025 with 20 aircraft committed in Block 1. Hanwha Ocean and HD Hyundai are competing for foreign submarine contracts and have positioned for the US Navy MRO market under the bilateral shipbuilding cooperation framework agreed in 2024.
Deterrence against North Korea remains the central organising threat. Pyongyang conducted multiple ICBM and SLBM tests in 2025 and continued tactical-nuclear exercises, prompting expanded US strategic asset deployments to the peninsula under the Washington Declaration framework. Roughly 28,500 US Forces Korea personnel remain stationed in country, with combined exercises Freedom Shield and Ulchi Freedom Shield scaled up. South Korea also faces a secondary China-related risk — Korea Air Defense Identification Zone incursions and East China Sea posture pressures. ROK forces participated in counter-piracy in the Gulf of Aden through the Cheonghae Unit and contributed liaison personnel to multinational Red Sea operations through 2025.
On 27 April 2026, SIPRI confirmed 2025 spending at $47.8B, with the increase driven mainly by the three-axis deterrence build-up. The KF-21 Boramae completed its low-rate initial production decision in mid-2025 and entered serial production at KAI Sacheon. In November 2025 South Korea signed a follow-on K2 tank executive contract with Poland (Wave 2, ~180 tanks of which 60+ produced in Poland). The 2024-2028 MTDP was reaffirmed in late 2025 with adjusted funding for the second Aegis BMD-capable destroyer batch and the CVX light carrier feasibility studies. The bilateral MASGA shipbuilding cooperation with the US progressed in early 2026 with Hanwha Ocean acquiring Philly Shipyard.
About 500,000 active personnel — Army 365,000, Navy 70,000 (incl. 29,000 Marines), Air Force 65,000 — backed by ~3.1 million mobilizable reservists. South Korea retains conscription with an 18-month Army service term.
SIPRI puts 2025 spending at $47.8 billion (2.6% of GDP), the 13th highest globally. The FY2026 MND budget approved by the National Assembly is roughly KRW 66.3 trillion. Five-year MTDP outlays are around KRW 348 trillion (2024-2028).
A 4.5-generation indigenous multirole fighter developed by Korea Aerospace Industries with Indonesian co-funding. It completed initial production decisions in 2025 and the first serial Block 1 aircraft entered ROKAF acceptance testing in early 2026. Total planned procurement is 120 aircraft.
High throughput, fast delivery schedules, modern designs, and a willingness to license co-production. Poland's post-2022 buy of K2 tanks, K9 howitzers, FA-50 jets, and Chunmoo MLRS — totalling tens of billions of dollars — established South Korea as a top-tier arms exporter.
South Korea's anti-North Korea strategy combining (1) Kill Chain pre-emptive strike, (2) Korea Air and Missile Defense (KAMD), and (3) Korea Massive Punishment and Retaliation (KMPR). Major procurement — Hyunmoo missiles, Aegis BMD, F-35As, KF-21 — supports all three pillars.