Yet in parallel to the increase in substate actor capabilities, there have been significant changes in U.S. capabilities. A major shift has been the emergence of options for the discrete and discriminate use of force. “Discrete” means the effective use of force apart from a large‐scale military campaign. “Discriminate” refers to the use of force against a very limited target set, indeed in many cases against single individuals with limited collateral effects. That option has made the use of force more effective for combating substate actors but also has made it more attractive, which is unsurprising given that much of the capability for discrete and discriminate use of force was developed precisely to make the use of force more attractive. This section briefly describes the emergence of that capability.
After Vietnam, both U.S. elites and the U.S. public were extraordinarily reluctant to use force for fear of another quagmire war. An example of that reluctance was the U.S. response to the Iranian hostage crisis in 1979. Both the elites in the Carter administration and the public broadly opposed the use of force. For example, as cited by Jack Snyder and Erica Borghard, one poll in November 1979 indicated “70% of respondents opposed a U.S. policy of bombing the main Iranian oil terminal if Iran put the U.S. hostages on trial, and 65% disapproved of a rescue attempt.” As time passed, the public became somewhat more hawkish on the use of force, but that support remained limited.22
The United States after Vietnam thus frequently faced a stark choice: either commit to a major conflict—for which almost no one had the stomach—or simply take no action. The Reagan administration spent the 1980s grappling with that reality. Sometimes, the administration was able to use force against a highly peripheral target (the invasion of Grenada or air or naval action against Libyan and Iranian targets). Yet at other times, it was forced to retreat rather than confront a challenge (the withdrawal from Beirut after the U.S. Marine barracks bombing).23 However, Vietnam and subsequent events drove changes in the way the United States generates and uses the military that allow more limited use of force. There are three critical changes: (a) the movement from conscription to volunteer military forces, (b) the emergence of precision bombing and supporting capabilities, and (c) the development of vast and robust special operations capabilities. Together, they significantly changed how the United States can and does use force.
The first of those changes, the shift to a volunteer military, was a direct outgrowth of the Vietnam War. American attitudes toward conscription have historically been ambivalent, at best, but the conflict in Vietnam brought hostility toward the draft to a crescendo. That hostility was most noticeable among those who were of draft age, and, as recently demonstrated by Robert Erikson and Laura Stoker, a high likelihood of call‐up for service in Vietnam had profound and enduring effects on the political beliefs of young men, even if they did not ultimately serve.24
Following several years of study, the Nixon administration formally ended the draft in 1973. It was replaced by a system that relied on attracting volunteers through a combination of incentives, including training and education, and opportunity (e.g., to “see the world”). The new system had initial problems, but within a decade had begun to produce a stable, high‐quality military force.25
Most notably, the fact that all service members were professional volunteers allowed the U.S. military, particularly the army, to take full advantage of a variety of new technologies and training techniques to enhance military performance. Those technologies included not only the emerging precision‐guided munitions, discussed next, but also the integration of computer technology into a variety of traditionally “low‐tech” systems, such as tanks and armored personnel carriers. The training techniques were exemplified by the National Training Center at Ft. Irwin, California, which used sensors across a wide area to enable highly realistic training.26
Even more important than the all‐volunteer military’s effects on military effectiveness is its effect on the domestic political constraints on the use of force. As noted, resistance to the draft peaked during the Vietnam War in large part because those at most risk of being drafted did not want to go to war. Resistance to the draft and resistance to the use of force thus became intertwined.27
However, with the all‐volunteer force, there was no need for young men (and women) who did not want to go to war to protest the war itself. They could simply ignore a war, and it, in turn, would ignore them. The same was true of their family members, friends, and political representatives. Those who volunteered for service, in contrast, did so accepting the possibility that they would be deployed to war. Thus, with a few exceptions, there was little protest from military families about the war in Iraq or Afghanistan.28
The result of that shift has been remarkably minimal public protest of all sorts of the wars in Iraq and Afghanistan. Public protest of the Iraq War peaked in September 2005 with a rally in Washington that drew more than 100,000 protesters. Subsequent rallies have been smaller, with a March 2010 rally in Washington drawing 10,000 or fewer.29 Moreover, the wars in Iraq and Afghanistan are the most massive, enduring U.S. uses of force, particularly ground force, since Vietnam. The more discrete and limited uses of force, from bombing Libyan forces to drone attacks in Pakistan and counterterrorism operations in Yemen, have produced even less public protest.
Those latter operations have been made possible by the second major change in U.S. military power: the emergence of precision bombing. More precisely, those operations are enabled by precision‐guided munitions, which enable incredibly accurate bombing from a relatively high altitude, combined with new systems for intelligence, surveillance, and reconnaissance that allow timely and accurate targeting. As a result of those advances, airpower, although far from omnipotent, is vastly more capable than even two decades ago.
Perhaps unsurprisingly, those technologies were born during the Vietnam War. In the Rolling Thunder series of air operations intended to coerce North Vietnam to end its support for insurgency in South Vietnam, the United States attempted to destroy many relatively small high‐value facilities (power plants, bridges, etc.). Those targets proved difficult to destroy with existing bombing techniques, requiring multiple attempts in the face of often‐intense air defense and concomitant loss of aircraft.
As a result, the U.S. military developed several systems for guid ing bombs to the target, rather than simply relying on gravity. Those systems culminated in the development of the first generation of laserguided bombs, which, when used during the Linebacker series of air operations in 1972, produced spectacular results and led to the term “surgical strike”—clearly a capability critical to discrete and discriminate use of force.30
The U.S. military continued to develop precision‐guided munitions after Vietnam, though the impetus for their development faded somewhat. In addition to bombs, precision‐guided missiles with long range, such as the Tomahawk cruise missile, were developed during that period.31 The United States also developed cheaper precision weapons based on Global Positioning System (GPS) technology.32
Precision‐strike capability has been a major enabler of U.S. uses of force since the 1990s, from Bosnia and Kosovo to strikes attempting to kill Osama bin Laden. One of the limitations that emerged, particularly in the bin Laden case, was the problem of locating targets, especially mobile targets. In response, the United States initiated work on new systems for intelligence, surveillance, and reconnaissance, most notably those carried by unmanned drone aircraft. Such aircraft could relay images or signals intelligence back to target planners, who would then be able to direct precision strikes much more effectively.33
Following the 9/11 attacks, both drones and precision strikes were a major element of the U.S. use of force. Precision strike capability was vital to the success of the 2001 campaign against al Qaeda and the Taliban in Afghanistan, where the United States had few troops.34 Drones were armed with precision weapons as well, resulting in the ability both to find and to destroy targets in a discrete fashion without risking U.S. personnel. Drones also enabled a certain level of plausible deniabil ity for use in covert campaigns, such as targeting al Qaeda and other militants in Pakistan’s tribal regions.35 That approach meant the United States could project discrete and discriminate force well short of a fullscale air campaign, much less an invasion.
The final change in the nature of U.S. military power is the creation of extensive and highly capable special operations forces. Although special operations forces are not a new concept, modern U.S. special operations forces are almost unique in size alone. The total personnel assigned to U.S. special operations is roughly two‐thirds the size of the entire British army.36 That quantity has a quality all its own, but in addition, the resources at the disposal of those forces for training and equipment are also unprecedented, producing a uniquely capable force with global reach.
That capability did not emerge from nowhere. As noted earlier, the failed rescue of the hostages in Iran in 1980 was an embarrassment to the United States. However, like the failures in bombing during Rolling Thunder, it also provided the impetus for major reform and improvement. The commission to investigate that failure, headed by retiredAdmiral James Holloway, argued for the creation of a multiservice (joint) special operations task force in order to provide the United States with a standing, integrated capability to conduct special operations, specifically with a focus on counterterrorism.37
The Carter administration accepted the commission’s recommendation and established U.S. Joint Special Operations Command (JSOC)in 1980. It provided a framework for integrating some existing special operations units as well as newly created units. According to some public accounts, since its inception, JSOC has conducted operations ranging from hostage rescue to the capture or killing of warlords and war criminals.
In 1987, still unsatisfied with the state of U.S. special operations, Congress enacted legislation that created a four‐star senior command over all special operations forces. U.S. Special Operations Command (USSOCOM, or SOCOM) created a high‐level advocate for all special operations, not just for those under the authority of JSOC. SOCOM became a powerful institutional champion for special operations in the United States. That champion, combined with the general support given to U.S. special operations in both Congress and the executive branch, revitalized U.S. special operations capabilities beyond JSOC. Most notably, forces from JSOC conducted a daring raid deep into Pakistan on May 1, 2011, to kill Osama bin Laden.38 That raid was perhaps the ultimate demonstration of the discrete and discriminate use of force.
Those three changes in the nature of U.S. military power are also mutually reinforcing. The shift from a military based on conscription to one based on professional volunteers has helped enable the training necessary to make full use of precision weapons while giving a highly qualified pool of personnel for special operations selection. Precision weapons provide effective fire support to small teams of special operators. Those teams, in turn, can provide intelligence and targeting for precision firepower.
Together, the changes represent a revolutionary change in the United States’ ability to use force. No longer are policymakers presented with the dilemma faced by the president and the public in the late 1970s and early 1980s of doing nothing or committing a major military force. Instead, individual terrorists or other suspects can be targeted almost globally by a combination of modern technology and a vast array of special operations forces.