The Limits of U.S. Military Capability: Lessons from Vietnam and Iraq

3 Leveraging the Adversary’s Support Base: States, Populations, and Societies

Given the challenges of influencing adversary leaders and maintaining domestic support for a US war effort, US policymakers understandably look to increase their leverage by turning to various “third parties” that provide active or passive support to the adversary. This chapter assesses US efforts to leverage (a) border states or outside powers that supported US adversaries in Vietnam and Iraq, (b) the populations that fed the Vietnamese and Iraqi insurgencies, and (c) the societal leaders and groups that were key to the US stabilization effort in Iraq. This chapter concludes that the United States was not positioned favorably to improve its leverage by extending the Vietnam and Iraq conflicts to other states and that the United States was unable to acquire the public following required to disrupt insurgent activities. In Iraq, unlike Vietnam, the United States was able to disrupt the insurgency indirectly by soliciting support from various societal leaders and groups. This approach can fail, however, when a society lacks cohesion or conflicts with its government. chapter three Leveraging the Adversary’s Support Base States, Populations, and Societies 84 The Limits of U.S. Military Capability States: Neighbors and Allies The United States can focus on the “supply side” of its security problem and try to obtain leverage by escalating conflict across international borders. By targeting states that provide aid and comfort to the enemy, the US goals, then, are (a) to obtain a capability advantage by destroying the enemy’s sanctuaries or infrastructure (training centers, supply depots) outside the immediate conflict zone and (b) to increase the costs and risks to a state that provides support voluntarily or involuntarily to the enemy. Yet, the danger for the United States in expanding the conflict is that it can add new fronts to the conflict or increase the motivation of all parties to resist. These costs become prohibitive in conflicts that are fueled largely “from within.” Aware of these dangers, the Johnson administration took extraordinary precautions to keep the Soviet Union and China out of the conflict and to prevent the conflict from spreading to adjacent states. Officials in the Johnson administration could not help but recall the chain of events, precipitated by the US crossing of the 38th parallel into North Korea, that provoked direct Chinese intervention in the Korean War. The Chinese offensive forced US troops to retreat and ultimately led to a military stalemate and long negotiating impasse.1 Johnson’s concerns were not misplaced. China adopted measures that made its intervention more likely: it moved forces into North Vietnam, including anti-aircraft artillery units that actively engaged US aircraft; prepared airfields in China adjacent to North Vietnam; committed, in principle, to employ planes based in China to defend North Vietnam and to send aircraft and pilots to the country; and tied its intervention to the US crossing of “green lines,” such as a US ground invasion of North Vietnam.2 Advised by the intelligence community that US bombing would not provoke China to intervene (Prados 2004), the Johnson administration still feared the effects of the United States expanding the conflict. So it ruled out a land invasion of North Vietnam, ground attacks on North Vietnamese sanctuaries and traffic routes in Cambodia and Laos, the mining of Haiphong Harbor, and strikes against certain targets (such as surface-to-air missile launchers that had not engaged US aircraft) and certain areas in North Vietnam.3 Conversely, the logic of expansion to counter the enemy’s military advantages motivated the Nixon administration to move against enemy sanctuaries in Cambodia in 1970 and Laos in 1971 (when the United States provided air support for South Vietnamese troops). Whereas prior US involvement in both countries was limited to covert missions, recruiting and aiding friendly forces, and aerial bomb- Leveraging the Adversary’s Support Base 85 ing, the United States invaded Cambodia to engage tens of thousands of North Vietnamese and Vietcong troops and destroy their base areas in the country. At least that was the objective. The practical effect of the operation was to push communist activities further into the interior of Cambodia, to increase North Vietnamese support for indigenous communist (Khmer Rouge) forces fighting the central government of Cambodia, and to remove any constraints that the Vietnamese communists observed in their deployments and operations in Cambodia. Indeed, with the overthrow earlier in the year...