South Korea ranks #5 of 170 militaries worldwide in 2026, with 500,000 active troops. The South Korean Army fields 13,232 ground vehicles, including 1,814 main battle tanks; the Air Force flies 1,566 aircraft, including 374 combat aircraft; the Navy operates 112 warships, including 20 submarines. South Korea has no nuclear weapons.
| Domain | Strength | Composition |
|---|---|---|
| Republic of Korea Air Force | 1,566 aircraft | 374 combat 869 helicopters 22 air bases +389 on order |
| Republic of Korea Navy | 112 warships | 51 major combatants 20 submarines 3 naval bases |
| Ground Forces | 13,232 vehicles | 1,814 main battle tanks |
| Personnel | 500,000 active | 3,100,000 reserve 3,013,500 paramilitary |
| Pillar | Weight | Score | Basis |
|---|---|---|---|
| Manpower | 10% | 99.6 | Active, reserve & paramilitary personnel |
| Ground forces | 20% | 75.9 | ARMS inventory power: armour & artillery by type and era, attack helicopters, armament |
| Naval power | 20% | 63.2 | SEAS inventory power: hulls by type, size and era, air wing, sustainment, armament |
| Air power | 25% | 53.4 | AIRS inventory power: aircraft by type and generation, enablers, armament |
| Nuclear deterrent | 10% | 0.0 | No declared nuclear capability |
| Defense budget | 15% | 55.7 | Annual spending, purchasing-power adjusted |
| Availability | modifier | ground ×1.04 · naval ×0.97 · air ×1.02 | Budget per point of each force, from the branch indexes |
| Population | 51.7M (2025) |
| GDP | $1.9 trillion (2025) |
| GDP per capita | $36,227 |
| Military budget | $43B (2025) |
| Share of GDP | 2.3% (2025) |
| Military spending per capita | $835 (2025) |
| Inflation rate | 2.12% (2025) |
| Capital | Seoul |
| Region | Asia |
| Land area | 99,909 km² |
| Coastline | 2,413 km |
| Land borders | 238 km |
| Bordering countries | 1 |
| Currency | KRW |
The Republic of Korea (ROK) is located on the southern half of the Korean Peninsula, bordered to the north by the Democratic People’s Republic of Korea (DPRK) along a 248-kilometer Military Demarcation Line. The primary security concern is the DPRK’s nuclear and ballistic missile program. Defense doctrine is centered on the Three-Axis System, which comprises:
The ROK maintains a bilateral Mutual Defense Treaty with the United States, providing the framework for the ROK-US Combined Forces Command (CFC). The United Nations Command (UNC) oversees the maintenance of the 1953 Armistice Agreement. Current strategic priorities involve the transition of Wartime Operational Control (OPCON) from the United States to the ROK and the expansion of maritime and space-based surveillance.
The Republic of Korea Armed Forces are managed by the Ministry of National Defense (MND) and directed by the Joint Chiefs of Staff (JCS). The ROK Strategic Command, established recently, coordinates the assets involved in the Three-Axis System.
Active personnel numbers are approximately 450,000, with a reserve force of approximately 3,100,000.
The ROKA is the largest branch and is structured into the Ground Operations Command and the Second Operations Command. Equipment includes:
The ROKN focuses on coastal defense and the protection of sea lines of communication. The ROK Marine Corps (ROKMC) operates as a quasi-fourth service under the Navy, currently undergoing a structural shift to increase the Marine commandant’s supervisory authority. Naval assets include:
The ROKAF maintains air superiority and provides precision strike capabilities. Equipment includes:
South Korea maintains a high degree of self-sufficiency in defense procurement, with domestic manufacturers providing the majority of land and naval systems. Defense exports reached $15.4 billion in 2025, positioning the ROK among the world's top arms exporters.
The government has established programs to integrate domestic technology start-ups into the defense supply chain, focusing on sovereign capacity in AI and satellite technology.
The ROK is implementing the "Defense Innovation 4.0" initiative to transition toward a technology-centric force. This shift is driven by a shrinking manpower pool caused by demographic decline. Procurement priorities emphasize unmanned systems, with a stated goal of developing 500,000 military drones by the end of 2026.
The 2026 defense budget is 65.8 trillion won (approximately $44.7 billion), representing a 7.5% increase over 2025. This allocation includes 19.9 trillion won for capability enhancement, specifically for the mass production of the KF-21 fighter and the acquisition of SM-3 shipborne interceptors. Current spending is approximately 2.5% of GDP, with a long-term target of 3.5% by 2035 to align with increased regional security requirements.
North Korea launched two short-range ballistic missiles from the Wonsan area toward the East Sea on September 20, 2026, one flying about 450 km and the other more than 600 km, South Korea's Joint Chiefs of Staff said; Japan said neither landed in its territorial waters.
After Japan's defense minister declined on September 11, 2026 to rule out nuclear-powered submarines, a technical explainer on how a reactor, a Stirling engine, a fuel cell and a lithium-ion battery each keep a boat under water, and what each one buys.
A Japan Air Self-Defense Force RQ-4B Global Hawk went down over international waters north of Tottori prefecture on 15 September 2026, the first loss of a Japanese Global Hawk and one of only 39 high-altitude surveillance drones GlobalMilitary.net records in service worldwide.
Hanwha Ocean was named preferred bidder for the Royal Thai Navy's next frigate on September 9, 2026; GlobalMilitary.net's inventories count 15 Korean-designed warships in seven foreign navies, nine of them second-hand corvettes.
Croatia signed with Hanwha on September 8, 2026 for 18 K239 Chunmoo rocket launchers, days after Spain ordered 128 K9 Thunder howitzers, as GlobalMilitary.net inventory data shows armies outside South Korea with more Korean armored vehicles on order than in service.
The US Navy has opened a formal evaluation of the Japanese Mogami, South Korean Chungnam and Turkish Istanbul frigate designs for a new class of frigates, USNI News reported on 1 September 2026, with the assessment due on 12 November.