Winning the Next War: Innovation and the Modern Military (1991) by Stephen Peter Rosen

Stephen Peter Rosen’s “Winning the Next War: Innovation and the Modern Military” (1991) came out just when the idea of a Revolution in Military Affairs (RMA) was coming into vogue in defence policy circles. It is one of the most influential books I’ve ever read. I discovered it my first year in graduate school at the Johns Hopkins School of Advanced International Studies (SAIS) and it heavily influenced my decision to pursue strategic studies as my academic and caeer focus.

In short, Winning the Next War is an incisive study of how military organizations adapt to the challenge of innovation. Rosen, a political scientist and former national security official, attempts to answer a vital question: How do military institutions, typically conservative and tradition-bound, adopt fundamentally new concepts of warfighting? In a field long dominated by technological determinism or cultural explanations, Rosen carves out a more institutional and political path, arguing that the key to innovation lies not only in ideas or technology but in peacetime promotion pathways and the politics of organizational change. His work stands out for its nuanced combination of theoretical rigor, historical case studies, and policy relevance.

The central thesis of Rosen’s book is that military innovation does not occur simply in response to external threats or technological shifts, but is driven by internal dynamics within military services, particularly the rise of new generations of officers. Rosen identifies two distinct forms of innovation: peacetime and wartime. Peacetime innovation is proactive and involves the development of new doctrines, structures, and promotion patterns in anticipation of future conflicts. Wartime innovation, by contrast, is reactive and often chaotic, marked by ad hoc adjustments in the face of immediate threats. Rosen focuses on the former, arguing that meaningful change requires senior military leadership to create new “promotion pathways” for young officers committed to new ideas, thereby allowing new schools of thought to compete for institutional dominance.

Rosen develops this framework through four detailed case studies: the U.S. Navy’s embrace of carrier aviation in the interwar period; the U.S. Army’s development of nuclear doctrine during the early Cold War; British Army innovation during the 19th century; and the emergence of the U.S. Air Force as a separate service. Each case illustrates how internal political coalitions, generational turnover, and the reallocation of organizational resources determine whether and how innovation succeeds.

In the case of U.S. naval aviation, Rosen traces how the Navy developed a powerful carrier force in the 1920s and 1930s, despite the dominance of battleship-centric thinking. Naval aviators were promoted in part through a redefined evaluation system that privileged aviation skills and allowed an alternative path to senior leadership. The naval aviation community created its own intellectual infrastructure, including dedicated schools and tactical doctrines, which allowed it to gain influence even before the proof of concept delivered at Coral Sea and Midway. Rosen convincingly shows that this was not a matter of technological inevitability, but of bureaucratic coalition-building and institutional foresight.

A similar logic applies to the U.S. Army’s handling of nuclear warfare during the early Cold War. Faced with strategic uncertainty, Army leaders initiated an effort to rethink doctrine around the use of tactical nuclear weapons on the battlefield. The Army’s introduction of the “Pentomic Division” in the 1950s was one manifestation of this effort. While ultimately flawed in practice, it represented a serious institutional attempt to reshape warfighting doctrine, supported by the rapid promotion of officers who championed these ideas. Here, Rosen emphasizes the link between intellectual innovation and career advancement, stressing that without such alignment, new ideas will not take root.

Rosen also draws on the British Army’s adaptation in the 19th century as a contrasting example of slower innovation. The British Army, operating in an era of imperial policing and limited wars, was often reluctant to adopt new organizational or technological ideas. Lacking a clear external threat and a strong institutional mechanism for internal reform, the army largely failed to innovate except in isolated episodes. Rosen uses this case to underscore the importance of institutional incentives and political leadership in driving meaningful change.

The final case study is the creation of the U.S. Air Force as an independent branch of the armed services. Rosen explores how strategic bombing theory, developed in the interwar years and applied with disappointing results during World War II, became the doctrinal foundation for a new service. Air power advocates not only developed a coherent theory of war but built an institutional coalition to support it. The founding of the Air Force Academy, the elevation of bomber pilots to senior positions, and the bureaucratic separation from the Army all played critical roles in making this innovation permanent. This example shows how successful innovation involves not just operational change but also the creation of new institutional identities.

Beyond these case studies, Rosen makes several broader theoretical contributions. He critiques earlier theories that focus exclusively on civilian intervention (as in the work of Samuel Huntington) or technological determinism (as often found in RMA literature). Instead, Rosen posits that military organizations can innovate from within, but only when the internal politics of promotion, resource allocation, and doctrinal legitimacy are aligned with the new vision. Civilian leaders have a role to play in supporting or constraining these processes, but the impetus must often come from within the military itself.

One of Rosen’s most important insights is his emphasis on generational change. Innovation often depends on the rise of a cohort of younger officers who were socialized into new ways of thinking. These officers must be promoted in sufficient numbers and to positions of influence if their ideas are to become institutionalized. Senior leaders must consciously open up promotion pathways and protect innovative thinkers from bureaucratic marginalization. This perspective reframes innovation not just as a matter of ideas or policy, but as a struggle over careers, identity, and organizational legitimacy.

Rosen’s arguments carry significant implications for contemporary military and policy debates. In an era of rapid technological advancement – from cyber warfare to artificial intelligence to autonomous weapons – his work serves as a reminder that successful adaptation depends not just on acquiring new tools, but on reshaping the human and institutional architecture of the military. The future of warfare will be shaped not only by emerging technologies but by who gets promoted, what they are trained to believe, and whether they are empowered to reshape doctrine and strategy.

Moreover, Rosen provides a model for understanding the failure of innovation. When promotion systems are rigid, when institutional identities are too narrowly defined, or when dissenting ideas are suppressed, militaries are more likely to repeat past mistakes or lose strategic initiative. The danger of “fighting the last war” is real, not because militaries lack imagination, but because they lack incentives to embrace the new.

Winning the Next War has become a foundational text in the field of military innovation and civil-military relations. It remains widely cited in defense studies programs, war colleges, and among national security practitioners. While the book was published in 1991, its relevance has only grown in the decades since, particularly in light of post-9/11 counterinsurgency campaigns and the current push for high-tech modernization.

Some critics have noted that Rosen’s focus on the internal military politics of innovation may downplay the importance of external shocks or civilian leadership. Others argue that the model may not apply as cleanly in non-democratic systems or in militaries where personalist leadership overrides institutional dynamics. Still, Rosen acknowledges these limitations, and the strength of his argument lies in its ability to explain a broad range of cases while offering a clear framework for further inquiry.

In sum, Stephen Peter Rosen’s Winning the Next War is a landmark work in the study of military innovation. Through rigorous case studies and a compelling theoretical lens, it provides a powerful explanation for how military organizations change – or fail to change – in the face of new strategic and technological realities. Its lessons are applicable not only to defense professionals but to anyone interested in how large, hierarchical institutions adapt to a world in flux. It is essential reading for students of military history, strategic studies, and institutional change.