The United States boasts an enviable record regarding the military’s role in politics: never a coup and never a serious coup attempt. However, this does not mean that the military always played only a trivial role in politics. On the contrary, as the Framers worried, it is impossible for a democracy to maintain a military establishment powerful enough to protect it in a hostile international environment without at the same time creating an institution with sufficient clout to be a factor in domestic politics.
The U.S. military’s political role has ebbed and flowed over the nearly 250 years of the nation’s history. The high-water mark of political influence came in the context of the gravest threat the country has faced, the Civil War, when the military enforced emergency measures approved by Congress, beyond the letter of the Constitution, including during Reconstruction when the military governed rebellious states of the former Confederacy. These were notable exceptions. For most of the 19th century, the military operated on the fringes of civilian politics, although through the Army Corps of Engineers it played a key role in state-building.
When the United States emerged as a great power with global interests, the political role of the military increased, though never in a way to directly challenge civilian supremacy. Today, the military wields latent political influence in part because of its enormous fiscal footprint and in part because it is the national institution in which the public express the highest degree of confidence. This has opened the door for myriad forms of political action, all falling well below the red lines that most concern traditional civil–military relations theory.
Military involvement in the American political system may be monitored and evaluated using a typology built around two columns that highlight the means of military influence—the first column is comprised of formal rules and institutions and the second encompasses the norms of military behavior with respect to civilian authority and civil society. While traditional civil–military relations theory focuses on military coups and coup prevention, theory based on this typology can help explain American civil–military relations, illuminating the warning signs of unhealthy friction under democratic governance and promoting republican vigilance at those moments when the U.S. military takes a prominent role and wades more deeply into domestic politics.
