H.R. McMaster’s 2020 book, “Battlegrounds: The Fight to Defend the Free World,” argues very powerfully for the centrality of historical understanding for addressing the world’s greatest challenges. Reflecting on U.S. approaches past and present, McMaster—retired lieutenant general, former national security adviser and himself a historian by training—suggests that “[i]gnorance or misuse of history often led to the neglect of hard-won lessons or the use of simplistic analogies that masked flaws in policy or strategy. Understanding the history of how challenges developed would help us ask the right questions, avoid mistakes of the past, and anticipate how ‘the other’ might respond.” McMaster claims that in dealing with adversaries it is important to appreciate rival interpretations of the past: “in order to overcome strategic narcissism, we must strive to understand our competitors’ view of history as well as our own.”

These are important insights, and never more so than in relation to terrorism—one of the problems McMaster dealt with in his distinguished military career. In responding to terrorism in practice, however, states have often been much less informed by historical insights than would have been life-savingly valuable. In the study of terrorism more broadly, historians’ voices have likewise been quieter than they need to be.

It is true that individual historians have made helpful contributions to the study of particular terrorist groups.  But—as pointed out recently in “The Cambridge History of Terrorism,” a new edited volume surveying the field—historical scholarship has been much less prominent in academic journals and on academic bookshelves than work drawn from political science, international relations, economics and psychology. Likewise, most academic centers focusing on terrorism are housed not in history but in other university departments.

Why is this? What has been lost as a result? And what should be done to change it? The answers to these questions are somewhat interlinked. Reflection on what a distinctively historical approach to terrorism offers illustrates why history has been a less salient discipline within approaches to terrorism, and also how it could better inform policy and public debates about the ongoing challenge terrorism poses for the United States and other countries.

So, what are the distinctive insights potentially brought by historians to an understanding of terrorism? First, historians consider the relationship between change and continuity with an eye to long pasts and, by implication, to long futures. This is a crucial aspect of properly understanding the long-rooted and long-term phenomena involved in the creation of terrorists and the outcomes of terrorist violence. The causes and consequences of 9/11 and the U.S.-led response can be properly appreciated only by analysis more historical than most that was applied at the crucial decision-making moments at the time. Historical scholarship on terrorism, for example, suggests that major terrorist adversaries endure for long periods and that, even after their strength has been weakened, they tend to continue in more limited form. President George W. Bush’s talk of finding, stopping and defeating every terrorist group of global reach was therefore ill-judged. Indeed, it misdirected energy toward the extirpation of a threat that should have been understood instead as eminently containable.

Second, historians stress the complex particularity and uniqueness of each context. This is not to deny that insights drawn from one case might be valuable in others. It is, however, to say that understanding terrorism and how best to respond to it requires deep contextual and historical knowledge. Regrettably, such knowledge has sometimes been lacking. It is telling to ask how many first-rate historians of Iraq, for example, thought plausible what was being promised by politicians in 2003 in relation to the U.S.-led endeavor there.

This complex particularity of terrorist context is—my third point—analyzed by historians through engagement with a vast range of mutually interrogatory sources, including many firsthand sources drawn directly from those people under scrutiny. At present, it remains unfortunate that so much research on terrorism is comparatively innocent of what terrorists themselves have said or left behind them. There is a credibility problem as a consequence, not least among the constituencies potentially sympathetic to terrorist groups.