Would North Korea Survive a Full-Scale War with South Korea and the United States? An in-depth assessment (2025)

In the autumn of 2025, as the Korean Peninsula remains one of the world’s most heavily militarized flashpoints, a single question continues to dominate strategic studies: If Kim Jong-un were to launch a general invasion or strategic nuclear strike against the Republic of Korea (ROK), would the North Korean regime survive the counterstroke?

The short answer, based on thirty years of open-source war gaming, declassified U.S. and ROK planning documents, and the current force posture, is unambiguous: No. The Democratic People’s Republic of Korea (DPRK) would be annihilated as a functioning state within days to weeks, and the Kim dynasty would almost certainly cease to exist.

The Asymmetric Balance of Forces on the Korean Peninsula (Late 2025)

North Korea’s Order of Battle

• Active manpower: ≈1.3 million (plus 7–8 million reservists of varying readiness)

• Artillery & rocket forces: 6,000–8,000 tubes, many hardened and within 50–100 km of Seoul

• Ballistic-missile arsenal: 1,000+ missiles, including Hwasong-17/18 ICBMs and KN-23/24 SRBMs

• Estimated nuclear warheads: 70–100 (U.S. intelligence community consensus, 2025)

• Chemical weapons stockpile: 2,500–5,000 metric tons (largest in the world)

Republic of Korea – United States Combined Forces Command (CFC)

• ROK active strength: 500,000 highly trained personnel, backed by 3.2 million reservists

• ROK Army: 2,600 modern tanks (K2 Black Panther dominant), 5,000+ K9/K55A1 self-propelled guns

• ROK Air Force: 180+ F-35A, 60 FA-50, indigenous KF-21 Boramae now in squadron service

• U.S. Forces Korea (permanent): 28,500 troops, THAAD, Patriot PAC-3 MSE, rotating armored brigade

• Immediate U.S. reinforcement (D+3 to D+10): 7th Fleet carrier strike groups, B-1B/B-2/B-21 wings from Guam and CONUS, additional Army and Marine Corps brigades

• Daily sortie generation in first week: >3,000 (ROKAF + USFJ + carrier air wings combined)

Probable Sequence of a Second Korean War

Phase I – Opening Barrage (H+0 to H+48)

North Korea would attempt to replicate the 1950 June offensive with modern tools: massed artillery and rocket fire on the Greater Seoul metropolitan area (25 million inhabitants) coupled with special forces infiltration and possible limited nuclear or chemical use. Casualties in the first 48 hours could reach several hundred thousand in the worst-case, no-warning scenario.

Phase II – Achievement of Air and Maritime Superiority (H+6 to D+5)

DPRK Air Force and mobile missile forces would be effectively destroyed. South Korean F-35s, U.S. F-22s from Kadena, and E-7/E-8 battle-management aircraft would establish air dominance at rates comparable to Operation Desert Storm (1991) and Operation Iraqi Freedom (2003).

Phase III – Counter-Battery and Deep Strike Campaign (D+3 to D+14)

ROK Hyunmoo-4/5 ballistic missiles, U.S. ATACMS, GBU-57 Massive Ordnance Penetrators, and hypersonic weapons (ARRW) would systematically eliminate 70–90 % of North Korea’s long-range artillery and remaining theater missiles. Hardened artillery sites in the Kaesong Heights and around Pyongyang would be reduced bunker-by-bunker.

Phase IV – Decapitation and Regime Collapse (Week 2–4)

Combined ground offensive (ROK I, III Corps and U.S. I Corps) would sever Pyongyang from its eastern and northern logistics bases. Known leadership bunkers, including the Ryongsong Residence and Kumsusan Palace complexes, would be struck. Any resort to nuclear weapons by the DPRK would trigger immediate U.S. strategic response under OPLAN 5015 and the 2022 Nuclear Posture Review.

Why Deterrence Holds – The Logic of Mutual Assured Destruction on the Peninsula

Every major U.S. and South Korean war game since the early 2000s – Millennium Challenge 2002, Ulchi-Freedom Guardian series, CSIS/RAND tabletop exercises – reaches the same conclusion: North Korea can inflict catastrophic damage on Day 1, but it cannot prevent its own annihilation thereafter. As General Vincent K. Brooks (former USFK commander) stated in 2017 and General Paul LaCamera reiterated in his 2025 posture statement to Congress: “They can start a war. They cannot finish one.”

Kim Jong-un is ruthless, but he is not suicidal. The regime’s overriding strategic objective is survival, not national martyrdom. Nuclear weapons and artillery are therefore held as instruments of deterrence and coercion, not as warfighting tools whose use would guarantee the end of the dynasty.

Conclusion: Annihilation Is Certain, Victory Is Not

A full-scale North Korean attack would result in the military destruction of the DPRK and the almost certain death or capture of its leadership. South Korea would suffer grievous losses – potentially the worst single-day civilian casualties since the Second World War – but the Republic of Korea and United States forces would prevail decisively.

The Second Korean War remains the least likely major conflict on earth precisely because both sides understand the outcome with crystalline clarity.

For further reading:

• CSIS “The Coming Korean Crisis” (2024 update)

• RAND “Deterring Attack on South Korea” (2023

• ROK Ministry of National Defense White Paper 2024

• U.S. Congressional Research Service “U.S.–South Korea Alliance” (October 2025)

  
  

The peninsula’s long peace is not an accident. It is the product of overwhelming military superiority and the mutual recognition that war would be regime-ending for Pyongyang.