No topic today unites and divides Americans more than war. But what does it mean? Even the people charged with its prosecution disagree. Former Secretary of Defense Donald Rumsfeld’s declaration shortly after the terrorist attacks on 11 September 2001 that “even the vocabulary of this war will be different” exemplifies the present difficulty in conceptualizing warfare.¹ The strong, and often vitriolic, clashes among senior officers in the Gulf War and the Balkan conflicts stemmed, to large degree, from their differing concepts of war. Today, as our armed forces fight a “Global War on Terror” (called—ironically, in some quarters—GWOT,...

During the Cold War, when many Americans believed they faced nuclear annihilation or communist dictatorship, the dangers posed a century earlier seemed insubstantial. But during this so-called “era of free security,” the perils were very real indeed to those concerned with the nation’s defense. Secretary of War John C. Calhoun warned Congress in 1820 that “however remote our situation from the great powers of the world and however pacific our policy,” it was almost inevitable that the United States would be drawn into another protracted war.¹

Calhoun did not need to remind his audience that the barely four-decades-old republic had...

Both to the officers who lived through them and to later historians, the three decades between the outbreak of the Civil War and the end of the Spanish-American War were a period of profound transformation. Americans reeled from the effects of the Civil War and Reconstruction, especially in the South, from immigration and the settlement of the western frontier, and from industrialization and urbanization in the East and Midwest. As big business arose along a progressive middle class, the sheer rapidity of modernization threatened to tear American society apart. In the military services, advances rippled out and overlapped at a...

In 1837 Major General Edmund P. Gaines unleashed a diatribe against military intellectuals who had “never seen the flash of an Enemy’s Cannon” and who drew all their insight on war from “mazes of French Books.” Instead, the nation should heed Heroes like himself, men whose long experience endowed them with a “common sense science of war” far superior to foreign theory.¹ Whatever the validity of Gaines’ critique, it glossed over an important fact: neither the general nor his fellow officers had been exposed to hostile cannon fire for at least two decades. Their combat credentials derived almost entirely from...

The war with Spain in 1898 revealed the army’s unpreparedness for modern warfare, and subsequent imperial commitments in the Caribbean and the Pacific stretched it to the breaking point. Appointed in 1899 with a mandate to reform the nation’s scandalously weak land forces, Secretary of War Elihu Root declared, “The real object of having an army is to provide for war.”¹ His annual reports outlined a comprehensive reorganization that included the creation of a chief of staff and a General Staff, a command and staff school, and the Army War College to educate officers in war planning. For the first...

A decade after serving as a chief of artillery for the American Expeditionary Forces and directing the AEF’s titanic bombardments on the Western Front, Major General William E. Lassiter recalled his observations of a recent war exercise: “Fine body of men, the 1st Cavalry Division. Excellent esprit, lots of vim—but operating as if they had been to sleep like Rip Van Winkle and knew nothing of machine guns, aeroplanes, etc. Obsessed with the idea that they must charge, and that modern weapons will not permit them to charge . . . And so they go careening over the open...

World War II proved to be the army’s finest hour. The defeat of Germany and Japan was a titanic military triumph, calling forth the service’s greatest effort since the preservation of the Union. The army’s recruitment, training, equipping, and transport of millions of citizen-soldiers across the globe, its development and production of weaponry, and the strategic insight and operational leadership of its commanders all proved its professional expertise. Yet at this moment of greatest triumph, the explosion of the atomic bomb at Hiroshima dramatically redefined modern warfare, making both the army and “conventional warfare” seem irrelevant.

Just when momentous changes...

In military parlance, Vietnam nearly broke the army. So deep was the bitterness, and so broad the army’s internal problems, that in the decade after 1972 the institution all but denied responsibility for the defeat. As oneWar College student rhetorically demanded in 1973: “Can a military subordinate be held accountable for a tactical error which occurs in the framework of a faulty national strategy?”¹ Convinced that others—politicians, the public, the media—were to blame, the army had little interest in analyzing the war’s lessons.

After both world wars, boards staffed by some of the service’s most respected commanders had...

A military institution’s concept of war is a composite of its interpretation of the past, its perception of present threats, and its prediction of future hostilities. It encompasses tactics, operational methods, strategy, and all other factors that influence the preparation for, and conduct of, warfare. During active hostilities, this vision must be focused on the here-and-now, on recovering from the last battle and preparing for the next one. Only after the guns fall silent, in the echo of battle, can military intellectuals refer to the lessons of centuries and contemplate a variety of futures. They can anticipate the effects of...