The militaries of every country conduct field and command post exercises to test their ability to perform missions dictated by their national leadership. Because three countries conduct such exercises regularly, numbering nearly two million soldiers in close proximity, the Korean peninsula experiences a heightened level of exercises—and tensions—that few other regions or countries share. Since the end of the Korean War, two antithetically opposed halves of one Korean nation have stood ready to attack or defend over a limited, mountainous terrain with massive armies with distinctly different capabilities and with the potential of killing hundreds of thousands of civilians in the early stages of a conflict.
For the Republic of Korea (ROK) and the United States, conducting exercises has required overcoming political, cultural, doctrinal and philosophical differences since the end of the Korean War to meet the North Korean threat from a combined posture. The history of US-ROK exercises is dominated by the evolution of the bilateral military relationship and this enduring threat, inter-Korean relations, and US-DPRK relations. The base justification for these combined exercises are the ROK-US Mutual Defense Treaty and the fact that the Korean peninsula remains in a state of war due to the signing of an Armistice Agreement in 1953 and not a peace treaty.
Historical developments have dictated four distinct phases of military exercises and their political-military context on the Korean peninsula: the early phase lasting from the end of the Korean War to 1965; the “Second Korean War” phase of 1966-75; the expanded capabilities phase of 1976-91; and the asymmetric capabilities phase from 1992 to the present. The one constant in all four is the continued conduct by North Korea of annual winter training exercises, offensive in nature, that culminate in the early spring and bring the North’s military readiness to its maximum level for that year.
US-ROK exercises have both military and political intent. They, of course, are intended to test their preparedness and the ally’s ability to conduct specific missions—in this case, to counter North Korean military adventurism. But there is also a political message for Pyongyang, namely that the alliance is prepared to protect the state, people and territory of the Republic of Korea and their combined interests while employing all the elements of national power to do so.
The Early Phase
The alliance’s combined exercises are a direct result of the “Pusan Letter” of July 7, 1950, presented by then South Korean President Rhee Syngman to General Douglas MacArthur, that passed operational control of ROK military forces for defense against North Korea’s attack starting on June 25, 1950. Then the Commander-in-Chief of US Far East Command, General MacArthur, passed operational control to his other command position, head of the newly established United Nations Command (UNC). After the war ended with the armistice, the UNC Commander retained operational control of South Korean forces, thus compelling alliance exercises to be combined, though not precluding national exercises designed to maintain unit readiness at lower levels. After the signing of the Armistice, the US began a steady drawdown of forces and the South Korean military began to rebuild and reconstitute under a moribund economy that limited its capabilities.
The early development phase was characterized by the ideological clash of communism vs. anti-communism, economic recovery that was initially more successful in the North than in the South, political instability in the South, and force-building on both sides. The first ROK-US combined exercise took place 16 months after the end of the Korean War in November 1955. The ROK Army 5th Corps and the US 5th Air Force conducted Exercise “Chugi,” or “Autumn Season,” under the supervision of the Tokyo-based US Far East Command, which supervised the UNC until 1957. Another exercise followed, designated “Spring Shower” and the two set the precedent for combined exercises that still exists today. Subsequent joint exercises, “Counterblow” and “Strong Shield,” focused on interoperability and command relations between the two militaries, maintaining a basic readiness posture and conducting counter-insurgency operations.
With the establishment of the US Unified Command Plan in 1957, the US Far East Command was replaced by the US Pacific Command and UNC headquarters moved from Tokyo to Seoul. After 1957 and up to the establishment of the Combined Forces Command in 1978, the UNC planned and led all combined exercises within the Alliance.
The “Second Korean War” Phase
North Korean provocations reached such a crescendo during the late 1960s that this period earned the reputation as a “second Korean War.” From 1966 to 1975, Pyongyang launched a steady series of provocations aimed at taking advantage of the US military commitment in Vietnam and the deployment of a corps-size ROK unit there to support that effort. North Korea’s military technology was very limited during this period, relying on whatever equipment and technology the former Soviet Union and China were willing to provide and thus unable to develop distinct military advantages difficult for the alliance to counter. However, North Korea began to slowly relocate much of its active-duty military forces forward toward the Demilitarized Zone (DMZ), thus reducing warning time and complicating battlefield defense strategies for the alliance.
Casualties were heavy on both sides as a result of these clashes. Over one thousand ROK soldiers and policemen and 171 civilians died as a result of North Korea’s armed infiltration operations while 111 American soldiers were wounded and 75 killed in action. This included 36 airmen who died as a result of the North Korean shoot-down of a US Navy EC-121M reconnaissance aircraft in 1969. Almost 300 North Korean infiltrators were killed in action inside South Korean territory. Other major provocations during this period included the 1968 North Korean attempt to assassinate ROK President Park Chung-hee, known as the Blue House raid; another assassination attempt in 1974 that resulted in the death of the South Korean first lady; and the 1968 hijacking of the US Navy intelligence ship, the Pueblo.
Beginning in 1968, the UNC revised its exercise program, replacing Counterblow and Strong Shield with “Focus Lens,” and also took advantage of the development of new approaches to war game simulations. One major response to lethal North Korean provocations took place during the first Focus Lens exercise of 1968 (infrequently referred to as Focus Retina). Three airborne infantry battalions from the 82nd Airborne Division flew 31 hours non-stop from North Carolina to drop south of the Han River in a show of how quickly the US could respond to North Korean hostilities.
The Expanded Capabilities Phase
The period from 1976 to 1991 was characterized by an increase in the size of combined ROK-US exercises; the November 1978 establishment of the ROK-US Combined Forces Command (CFC), which assumed leadership and planning of all combined exercises (and continues to this date); the modernization of the ROK economy; and the dramatic expansion of the North Korean military to over one million men on active duty, as well as its continued deployment of forces in a forward posture.
In 1976, the South Korean readiness exercises, designated Ulchi, and Focus Lens were integrated to create an expanded exercise that combined South Korean government and combined command post exercises for a broader approach to defense of the ROK. Held annually in late summer, Ulchi Focus Lens, or UFL, ultimately became the largest computer-assisted simulation exercise in the world.
Additionally, beginning in 1976, the alliance introduced a new exercise, dubbed “Team Spirit,” that emphasized force flow and force-on-force operations. The ability of the United States to flow forces to the Korean peninsula in case of conflict was a critical component of operational plans and also demonstrated a continued strong commitment to the defense of South Korea. Those forces would then exercise with major units opposing each other in simulated battle. Conducted in the early spring, Team Spirit served to unite several smaller exercises into one large one emphasizing field-maneuver. It grew over the years from an initial participation of 107,000 US and South Korean troops to over 200,000 in the late 1980s.
Because of its size, Team Spirit became a major concern for the North Koreans. It became a key issue in Washington-Pyongyang negotiations during the nuclear crisis of 1993-94. Visiting North Korean leader Kim Il Sung in 1993, New York Congressman Gary Ackerman stated that Kim’s voice “quivered and his hands shook with anger” at the mention of Team Spirit.
The combination of Ulchi Focus Lens and Team Spirit during this phase was a major step in the ROK-US alliance efforts to improve South Korea’s defense posture. However, toward the end of this phase, North Korean capabilities began to go “asymmetric,” namely by fielding of non-conventional weapons systems that were extremely difficult to counter with conventional forces. Most importantly, Pyongyang began programs to develop weapons of mass destruction and the systems to deliver them.
The Asymmetric Capabilities Phase
Beginning in 1992 and lasting until today, this phase is characterized by North Korea’s development of nuclear and missile programs; the deployment of long-range artillery north of the DMZ capable of striking all of Seoul and most of its suburbs; the fielding of 200,000 special operations troops; the high degree of nuclear tensions; the advancement of the North’s cyber warfare capability; and the transition of operational control of South Korean forces back to Seoul’s wartime control.
Moreover, North Korea’s political stability during this period was significantly challenged by a failing economy and the great famine of the 1990s that took the lives of somewhere between 500,000 to 3,000,000 North Koreans, depending on which source is cited. This had a distinct impact on the stability of the North Korean regime and suggested scenarios in which the North Korean military could react in unpredictable ways that directly threatened South Korea. Would economic collapse cause the collapse of the North Korean regime? If so, could this lead to civil war that might spill over into the South? Would a failing regime order an attack on the South to avoid losing power?
These changing conditions required changed responses intended to cope with important challenges such as dealing with a dramatically evolving threat, who is in the lead—ROK or US—and at what point in crisis, and how does interoperability change with different leadership?
From 1991 to 1996, Team Spirit became both a carrot and a stick during US negotiations with North Korea over its burgeoning nuclear program. This exercise was cancelled in 1992, carried out again in 1993, and planned but not executed from 1994 to 1996 as a result of negotiations that led to the 1994 US-DPRK Agreed Framework and efforts to ensure the framework remained in effect. Team Spirit was then replaced with a command post exercise known as “Reception, Staging, Onward Movement, and Integration” (RSO&I)—which was conducted from 1994 until 2007 along with “Foal Eagle,” a series of tactical level exercises taking place in the spring. These exercises were much smaller than Team Spirit but maintained staff readiness in the conduct of flowing US forces to the peninsula.
In 2007, RSO&I was replaced by “Key Resolve” (a command post exercise that trains staff instead of field units). Key Resolve and Foal Eagle (the exercise for field units) run near simultaneously and continue to be carried out. Ulchi Focus Lens continued until 2007 when it was succeeded by “Ulchi Freedom Guardian” (both command post exercises) to reflect changes of leadership within the alliance.
The legacy of the ROK-US combined exercises is not only vastly improved readiness in the defense of South Korea and the continued deterrence of large-scale conventional attacks by Pyongyang, but also North Korea’s healthy respect for the combined force posture of the alliance. For the future, there are a number of issues that may change how the allies conduct combined exercises. For example, the operational control of the South’s forces is scheduled to transition to the ROK in 2015, putting South Korea in charge of decision-making, and planning. Second, when and if North Korea is deemed capable of mounting nuclear warheads on delivery systems able to reach the United States, exercises will have to be adjusted to reflect the new requirements for defending American allies as well as the United States. These challenges to the alliance will require military and civilian dedication, supreme effort, artful leadership and not just a few dollars to accomplish.
 The Korean People’s Army (North Korean military) has always trained with offense in mind. The differences from one year to the next are based in the increased size of its military, the evolution of its weaponry and the positioning strategy of its forces.
 United Nations Security Council Resolution 84 of July 7, 1950 established a unified command under the United States for the purpose of responding to North Korean aggression and urging United Nations member states to contribute forces to the US-led command. Once the United Nations authorized a “unified command” under the US, the order establishing the United Nations Command was Communique Number 135 of the Far East Command S/1629 25 July 1950. See United Nations, Yearbook of the United Nations, 1950, http://unyearbook.un.org/1950YUN/1950_P1_CH3.pdf.
 Interview with the Eighth Army historian, February 10, 2014.
 Daniel Bolger, Scenes From a Unfinished War: Low-Intensity Conflict in Korea, 1966-1969 (Fort Leavonworth, Kansas: Combat Studies Institute) Leavonworth Papers No.19, June 1991, http://usacac.army.mil/CAC2/cgsc/carl/download/csipubs/ScenesFromanUnfinishedWar.pdf.
 Computer-assisted simulations offer the cost benefit of not actually deploying forces on the ground through simulating military movements via newly developed simulations in the cyber world.
 John Farrell, “Team Spirit: A Case Study on the Value of Military Exercises as a Show of Force in the Aftermath of Combat Operations,” Air and Space Power Journal, Fall 2009.