Path Dependence
I have long believed that past decisions constrain future options. In other words, decisions are not made in a vacuum; historical context plays a significant role and decisionmakers often face limitations on their freedom of action. Current options may be constrained by past actions.
U. S. involvement in Vietnam provides a good example of path dependence. After World War II, the French attempted to reimpose colonial rule in Indochina. Led by Ho Chi Minh, the Vietnamese fought back. The 1954 Viet Minh victory over the French at Dien Bien Phu spelled the end of French colonial rule in Indochina. After the French withdrawal, Vietnam was divided at the 17th parallel. This division was meant to be temporary pending national elections. The United States cancelled the elections when it appeared certain Ho Chi Minh, communist leader of North Vietnam, would win.
South Vietnam was led by Ngo Dinh Diem, a staunch Catholic whose religious views were suspect to the majority Buddhist South Vietnamese people. Diem’s corrupt regime had difficulty maintaining popular support and came under increasing pressure as a pro-communist (Viet Cong) insurgency gained traction in the countryside. By 1963, South Vietnamese generals were openly plotting a coup against Diem. The generals asked for, and received, U. S. support. The coup occurred in November 1963 and ushered in a period of instability in which a whirlwind of South Vietnamese leaders assumed power only to be quickly replaced by a rival. Having sanctioned the coup against Diem, the U. S. could do little more than watch as events unfolded.
After the Gulf of Tonkin incident in August 1964, President Lyndon Johnson authorized airstrikes on targets in North Vietnam. In March 1965, Marines landed at Da Nang, in South Vietnam, to provide security for the U. S. airbase located there.
Escalation followed as both the North Vietnamese and the U. S. poured more troops into South Vietnam. General William C. Westmoreland, commander of the U. S. Military Assistance Command, Vietnam (MACV), focused U. S. troops on the big unit war against the North Vietnamese Army (NVA). Westmoreland shunted aside the South Vietnamese armed forces and relegated them to pacification duties. Preparing the South Vietnamese military for the day when American troops would inevitably depart was a low priority for MACV between 1965 and 1968.
Things changed in 1968. The Tet Offensive, although a military disaster for the NVA and VC, had been a shock to Americans who believed the war’s end was in sight. Anti-war protests across the U. S. clearly demonstrated support for the war was waning. In November, Richard Nixon was elected President. One of Nixon’s campaign pledges was to end the Vietnam War.
Soon after taking office, Nixon announced a policy of “Vietnamization” in which South Vietnamese troops would take over responsibility for fighting the war. Once South Vietnamese Armed Forces (RVNAF) units were trained and ready, they could relieve departing U. S. troops. General Creighton Abrams, who had replaced Westmoreland at MACV in mid-1968, was responsible for implementing Nixon’s Vietnamization strategy.
Vietnamization faced significant challenges. Time was short. Nixon was under enormous — and increasing — pressure to get U. S. troops out of Vietnam. The result was that the timetable to withdraw U. S. troops was de-linked from RVNAF readiness. U. S. troops would leave Vietnam and the RVNAF would assume responsibility for fighting the NVA and VC whether the RVNAF was ready or not. The RVNAF also faced organizational difficulties.
The RVNAF was created in the image of the U. S. armed forces. This meant the RVNAF fought battles using massive firepower and required expensive and consistent logistical support to maintain all the equipment they had received from the U. S. If the U. S. stopped providing significant financial and military support, RVNAF capabilities would quickly degrade (which is ultimately what occurred in 1975).
This brings us back to the idea of path dependence. What if in 1965 the U. S. had demanded the Government of South Vietnam and RVNAF effectively address corruption and had simultaneously begun a program of building RVNAF into an effective counterinsurgency force? Would this have changed the outcome in Vietnam? We can never know. What is certain, however, is that by 1968 past decisions had taken these options off the table. The only real option left was Vietnamization and we know how that turned out.
The concept of path dependence is more than academic; it has important implications for military planning. We sometimes believe when selecting between options if one course of action does not work out, we can always go back and try the other. This may be possible, but the concept of path dependence cautions us that circumstances will often have changed. The discarded option may no longer be viable or — if it is — it may now be suboptimal. There is no doubt leaders and planners already consider their options to select the most effective course of action; they also need to carefully consider how their choices may limit their future freedom of action.