“I was thinking, as I often do these days, of war,” so Marilyn B. Young titled her 2011 presidential address to the Society for Historians of American Foreign Relations (SHAFR). Her passing in 2017 and her capacious sense of war shape this essay. She also gently corrected me, “The shadow of war, as Michael Sherry called it fifteen years ago, seems not to be a shadow but entirely substantial: the substance of American history.”Footnote ¹ So it is. War was the engine of the state, as Randolph Bourne pointed out in 1918, and the prototype for much else the state did. War constituted modern American history as much as race, class, gender, religion, capitalism—you name it—just as each threaded through the others. Too few historians fully engage that fact.

I have been “thinking of war” most of my life. Born in 1945, I first encountered war on flickering screens: television news about the Korean War; NBC's series Victory at Sea (1952–1953), about naval warfare during World War II; Gone with the Wind (1939), probably during its theater re-release in 1954; Frank Capra's documentary cum propaganda series Why We Fight (1942–1945), taken from the local public library to a home projector in our basement. In school came the dismaying moment on December 6, 1957, after Sputnik had circled the planet, when we watched the televised launch of America's Vanguard TV-3 rocket, which toppled over and exploded (“Flopnik, Kaputnik, Oopsnik, Stayputnik”).

Beyond such visual fragments, little else in Muncie, Indiana, made war palpable. No one in my family orbit had died in military service. Local factories had resumed civilian production (or entered early-stage de-industrialization). No military bases were nearby. Enlisted or drafted boys were working class; middle-class boys in my milieu went to college (some also to ROTC, one to West Point), or married and fathered children, exempting them from the draft. The threat of war came home most jarringly in angry dinner conversations about who should build bomb shelters and who could enter them. Because 1964 GOP presidential nominee Barry Goldwater had married a wealthy local woman and Planned Parenthood advocate Margaret “Peggy” Johnson, his saber-rattling 1964 campaign got lavish local attention.

But by then I was in college (1963–1967). The co-incidence of college with the Vietnam War played on my childhood anxieties to forge my politics and professional interests. In the mix were scary movies like Sidney Lumet's Fail Safe (1964) and Stanley Kubrick's Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb (1964), barroom talk, fears of being drafted (I never was), and anti-war protest. I was taught at Washington University by historians—many, I realize better now, directly shaped by war—attentive to war's history and enraged about America's Vietnam War. Theodore Von Laue (son of anti-Nazi Nobel physicist Max Von Laue, pioneer of global history, anti-war Quaker) and Barry Karl (wise historian of the U.S. state) influenced me quietly (good teaching “also means playing your role pianissimo,” Von Laue later wrote).Footnote ² My senior thesis was on James Forrestal, the first Secretary of Defense (and the only one to commit suicide).

Neither then nor later did I take a course billed as military history or get taught by a military historian. To me, war included military history, but also seemed far bigger than that category. That outlook stemmed in part from devouring Arms and Men: A Study in American Military History (1956) by Walter Millis, who saw freedom being “extinguished” by the big powers’ defense policies, which “spread a corroding sense of insecurity” and augured “the extinction of civilization, if not of humanity itself.”Footnote ³ My Ph.D. advisor John M. Blum also helped me grasp war's less obvious dimensions, hence a Yale dissertation titled “Preparing for the Next War: American Plans for Postwar Defense, 1941–45” (1975).Footnote ⁴ In the 1970s, enough young (male) historians chose to study war for me to sense there was a scholarly tide to enter. In the process, I formulated the obvious, blunt question: Why did the United States go to war so often, destructively, unnecessarily, unproductively? I've been at it ever since, tracing war's “causes,” conduct, and consequences (“war on crime,” in my current work).

Now, war is less at the center of scholarship and teaching about modern American history, though at the periphery of much of it. Or so I see it, acknowledging that no one, especially at my age, reads everything. Many issues of the Journal of American History slide by with little attention to it, especially its twentieth-century version. Diplomatic History, the main journal of the Society for Historians of American Foreign Relations (SHAFR), does more, but often it seems as if “foreign relations” does not quite encompass “war,” despite Marilyn Young's plea that it do so. Among numerous panels for the April 2017 Organization of American Historians meeting, three appeared to engage war directly. Perhaps journal editors and program committees shove aside the stuff I want, but more likely little of it reaches them. (It does reach the Society for Military History, whose 2017 conference was capaciously titled “Global War: Historical Perspectives.”) Fortunately, books still appear with the sweep of Russell Weigley's The American Way of War: A History of United States Military Strategy and Policy (1973) and H. Bruce Franklin's War Stars: The Superweapon in the American Imagination (1988). My picks include Andrew Bacevich's work (like Millis, a historian who engages the public); The Dominion of War: Empire and Conflict in North America 1500–2000 (2005) by Fred Anderson and Andrew Cayton; and John Dower's Cultures of War: Pearl Harbor, Hiroshima, 9–11, Iraq (2010).Footnote ⁵ And exciting work appears on particular but daunting topics.Footnote ⁶ But few graduate students I encounter tackle topics squarely related to war or seem keenly engaged in readings about war. For many of them, World War II is something of a blank spot—they hardly deny its importance, but they slide fast from the 1930s to the postwar.

Why has the study of war drifted toward the sidelines since the 1970s? The advent of new subjects played a role. No one I knew in graduate school did queer history, food and hunger, or “non-state actors” (we studied them but did not yet know to call them that). Now we have much else to tackle. Generational experience must be part of it. Just as few scholars plumbed agricultural history once most Americans left farm life, few now are as directly touched by war as earlier generations, for all the “global war on terror” or Donald Trump's rants that inform their lives and inflame their politics. Put crudely: as fewer Americans die in war (whether fewer die at American hands is harder to measure), fewer study it.Footnote ⁷

And war changed. It lost the boundaries it once seemed to have, when nations declared war, big operations unmistakably marked wars’ start, and formal surrenders marked their end. The United States, of course, mounted other military operations, too, most in non-European lands, but those did not establish the template by which Americans understood war. With the United States's slide into the Vietnam War, that template eroded, and after a pause during Jimmy Carter's presidency, the United States engaged episodically, and after 9/11 continuously, in military operations that lacked the borders war once had, despite President George W. Bush's attempt to analogize the 9/11 attacks to Japan's attack at Pearl Harbor. Another border, around the state, also eroded, as non-state forces (sometimes supported by states) took the field, right-wing groups pursued a “global brotherhood of paramilitaries” to replace what they saw as a failed American state, private contractors took on more tasks of states’ war-making, and “terrorists” roamed much of the globe.Footnote ⁸ The legal and geographical borders around war faded, as did those regarding time.Footnote ⁹

As an object of study, war became harder to get a fix on. As war diffused across the literal and imaginative landscape of the world, the study of it diffused across the landscape of historical scholarship. That diffusion was understandable: our scholarship mirrors the real world (as we perceive it), and scholars now study war with a bracing variety of methodologies and perspectives. Still, with war everywhere—but nowhere in particular—it was easier to lose sight of it. Scholars probed war's murky borderlands, but perhaps privileged the borderlands over war itself (“war itself” is an iffy term, of course, implying an essential core to it that may not exist).

As war's borders dulled and its American casualties declined, so too did the public discourse about it that influences what scholars study. When I re-watched King Vidor's The Big Parade (1925), about U.S. soldiers in World War I, I was struck anew by how utterly silent it was about the causes of that war (beyond mindless patriotism) and the virtue or evil of its combatants—and this in reportedly the highest-grossing (at least MGM's) movie of the silent era. If not the “anti-war” film Vidor later claimed it was, “pro-war” would be a stretch. Do we have anything like it today? One contender is Ben Fountain's novel Billy Lynn's Long Half-Time Walk (2012), and the Ang Lee movie derived from it. But the movie bombed.

Few things are more tiresome than historians’ complaints that their fields are neglected (responses to those complaints get tiresome too). Why don't we have more political history, military history, women's history, or …? But my plea is for more attention not to a field, but to a subject—one that can be examined by any subfield, from art history to women's history. It's a plea to recognize the centrality of war to modern American history, not to bolster the (supposedly) sagging fortunes of any subfield.

Perhaps war is also hard to study because historians seek to find causes and identify agency. I once regarded the United States as a nation reluctant to go to war but entering it because of pressures and “causes.” Now I think of it as a nation deeply wedded to and defined by war, though maddeningly reluctant to admit it. I came to sense, more so with each war, that the United States went to war simply because it could, for no more compelling reason than its ability to do so; since it excelled at war, retaliation against it was unlikely, and direct experience of war was rare for most Americans. War—gearing up for it, waging it, imagining many things in terms of it (“war on drugs”)—is what the nation does. The United States excels at war, though no longer at winning it. Historians should find the causes of war and the forces behind it in each instance: economic interests, strategic calculations, political machinations, sham patriotism, war-hugging movies, threats from enemies, twists and turns of international systems. But the practice outlasts each instance. It is a habit, perhaps not “caused” by anything of the moment, and a habit is harder to account for than an instance. William Appleman Williams saw Empire as a Way of Life (1980). We might also see war as a way of life.

“War: What Is It Good For?” was the question Marilyn Young posed for a forum to honor her at the 2017 SHAFR meeting. She did not assume a simple answer, like “nothing.” It remains a great question for scholars of modern American history.