"The foreign policy and defense communities have intensively debated the efficacy of low-cost and small-footprint military options for crises such as those in Afghanistan, Iraq, Libya, Somalia, Syria, and Yemen. This report divides these operations into three types: limited stabilization (involving the deployment of hundreds or thousands of ground forces to bring a conflict to a favorable end), limited strike (involving airpower — predominantly drone strikes — to disrupt and degrade militant networks), and indirect options to contain or mitigate a conflict. The report provides a statistical analysis of hundreds of cases, supplemented by case studies, to evaluate the strategic effects of each type of operation. Limited stabilization missions can improve the odds of achieving an acceptable outcome at relatively low cost, but the odds of outright military victory are generally small. Larger numbers of forces, on average, yield better outcomes, but only at extremely high cost. The United States can instead rely on partners to conduct these operations, but doing so often comes with numerous drawbacks. Limited strike operations can disrupt militant networks — but generally only when they are conducted intensively and in cooperation with a reasonably effective partner on the ground. Where these conditions do not hold, such strikes appear to have counterproductive effects, including increased militant attacks and propaganda activity. Finally, indirect options were found to have limited effects. Efforts to bolster front-line states to prevent conflict spillover did not have any observable effect. Safe areas, no-fly zones, and interdiction campaigns can all provide important benefits — but usually as elements of a larger military operation, not as alternatives to large-scale intervention."--Publisher's description.

"Prepared for the United States Army"--Title page. Also available as PDF from RAND.