This chapter surveys almost 170 years of historical practice of and writings on irregular warfare to stress several points. It provides an empirical basis for assessing current and future irregular warfare based on codified doctrine, including best practices and observations. From the American Revolutionary War to the Second World War, several key themes emerge, including the necessity of force, the counterproductive nature of brute force and the value of objective as opposed to subjective assessments of contextual conditions. In doing so, this chapter seeks to deflate some of the influence of ‘presentism’, a bias that suggests recent experiences are unique and indicative of the future of irregular warfare. In stressing historical continuity, it acknowledges continuous elements in irregular warfare while recognising context differences.

Chapter 1 establishes the foundational concepts of neuroimaging by exploring the complex relationship between brain structure and mental function. It traces the historical progression from ancient surgical approaches to modern noninvasive techniques, contextualizing how technological innovations have transformed our understanding of neural processes. The chapter examines the multiscale nature of brain investigation, from single-neuron recordings to population-level measurements, and evaluates the critical tradeoffs between spatial and temporal resolution across imaging modalities. Key neurophysiological principles underlying these technologies are introduced, including neuronal action potentials, hemodynamic responses, and the chemical processes that support neural activity. The text challenges common neuromyths while addressing fundamental questions about functional organization, from modular specialization to distributed network processing. By comparing the relative strengths and limitations of major neuroimaging tools (fMRI, EEG, MEG, PET, and TMS), the chapter provides an analytical framework for understanding how these methodologies collectively advance our ability to correlate brain activity with cognitive and behavioral processes, setting the stage for more detailed exploration in subsequent chapters.

Despite debates on the revolutionary impact of such concepts as blitzkrieg, modern land warfare has had a strong evolutionary dynamic. This chapter argues that modern tactics emerged during the First World War as a result of the need to cope with significant increases in firepower. Further, building on theories developed during the inter-war period, the concept of operational art emerged in practice during the Second World War as a means of connecting tactics to strategy. Modern system tactics and operational art remain at the heart of modern land warfare, although the latter, especially in terms of the idea of a distinct operational level of warfare, remains controversial.

This chapter tackles positron emission tomography (PET), a functional neuroimaging technique that revolutionized brain imaging in the 1970s by providing the first colorful maps of brain activity. Beginning with its historical development from Hans Berger’s early hemodynamic measurements to modern scanners, the chapter examines how PET visualizes metabolic processes by tracking radioactively labeled tracers in the bloodstream. Unlike structural imaging methods, PET detects gamma rays emitted when positrons from the radiotracer collide with electrons, allowing researchers to measure regional changes in blood flow, glucose metabolism, and neurotransmitter activity related to cognitive processes. The chapter details practical aspects of PET studies, including experimental design, data acquisition, image reconstruction techniques, and visualization methods like subtraction analysis for mapping task-related brain activity. While MRI-based techniques have supplanted PET for many cognitive neuroscience applications, PET remains invaluable for certain investigations due to its unique ability to label diverse compounds, particularly for studying neuropsychiatric disorders, neurotransmitter systems, and metabolic processes in diseases like Alzheimer’s and epilepsy.

This book focuses on modern warfare. It examines the conduct of war in its different environments and forms and provides an introduction to the issues, ideas, concepts, context and vocabulary necessary to develop an understanding of the subject. It is not a history book, although relevant historical examples are used throughout to illustrate the analysis. Rather, the book is designed to equip the reader with a sophisticated introduction to the concepts, issues and debates that will help them to understand current concerns and future possibilities and also to unpick past campaigns.

Chapter 7 deals with neuroimaging methods for investigating the structural components underlying brain function. Beginning with lesion-symptom mapping (LSM), which identifies relationships between localized brain damage and specific cognitive deficits, the chapter examines how structural abnormalities correlate with functional impairments. Three primary approaches to measuring brain structures with MRI are discussed: structure tracing for hypothesis-driven volumetric analysis, voxel-based morphometry (VBM) for whole-brain comparison of tissue concentration, and surface-based morphometry (SBM) for analyzing the cortical sheet’s unique properties including thickness, curvature, and gyrification. The chapter then explores diffusion tensor imaging (DTI), a technique that visualizes white-matter tracts by measuring the anisotropic diffusion of water molecules along axon bundles. DTI tractography reveals the brain’s “highways,” short, intermediate, and long-range fiber pathways that connect functional modules within and across hemispheres. Together, these complementary techniques provide critical insights into the structural architecture supporting brain networks, offering a more complete understanding of brain organization when combined with functional imaging methods.

Chapter 9 introduces transcranial magnetic stimulation (TMS), a neurostimulation technique that uses rapidly changing magnetic fields to induce electric currents in targeted brain regions. Beginning with its historical roots in 19th-century electromagnetic experiments and evolving through Anthony Barker’s groundbreaking 1985 demonstration, TMS has become a critical tool for establishing causal relationships between brain activity and behavior. Unlike neuroimaging methods that only observe brain activity, TMS can temporarily interrupt or enhance neural processing, enabling researchers to create “virtual lesions” and directly test hypotheses about regional brain function. The chapter examines TMS delivery methods, single-pulse, paired-pulse, and repetitive stimulation, and their differential effects on cortical excitability. It details four primary research applications: virtual lesions for establishing causality, chronometry for determining processing timelines, mapping functional connectivity between brain regions, and tracking neuroplasticity. Clinical applications are discussed, particularly for treating depression and presurgical mapping. The chapter also addresses practical aspects of TMS implementation, localization techniques, and safety considerations, concluding with a brief overview of transcranial direct current stimulation (tDCS) as a milder alternative stimulation approach.

This chapter examines the employment of air and space power in the twenty-first century, considering possible future developments in air and space power out until the year 2040. It notes the growing role of commercialisation in the delivery of air and space power and how businesses such as SpaceX have become a part of military operations through contractorisation. The chapter notes how Western air power advantages have been eroded by developments in Chinese aerospace and the proliferation of increasingly sophisticated missile systems. The rise of drone warfare is covered, along with the procurement of a range of drone and missile systems by non-state actors such as Hamas and Hezbollah; the chapter concludes with considerations of the ways in which this presents challenges going forward and a repudiation of the suggestion, presented by commentators such as Van Creveld, that the ’age of air power’ had drawn to a close.

Cyber warfare has attained a growing prominence in debates on contemporary and future warfare. Cyber tools are an important element in the conduct of information operations and cyber is commonly viewed now as a separate domain of warfare. The cyber domain has a range of attributes that appear to give it some unique advantages over the traditional warfare domains. This has led some commentators to argue that it is an increasingly decisive element in warfare, perhaps even able to substitute for traditional land, air and maritime forces. But there are counter-arguments that hold that cyber warfare has significant weaknesses as a tool and that it is an important, but still complementary element, in modern warfare.

This chapter builds on the analysis contained in the environmentally specific chapters in this book and explores the challenges and opportunities associated with joint warfare and joint operations. It examines the history of such operations and explains why they have tended to be so difficult to conduct successfully, before then addressing alternative approaches to the conduct of joint operations and to the command and control of such operations. The chapter then addresses current ideas relating to joint warfare and to concepts of multi-domain integration and multi-domain operations. These are explored with reference to the strategy and doctrine of a number of different armed forces, including the latest US developments in this field.

Chapter 2 traces the development of electroencephalography (EEG) from its inception with Richard Caton’s pioneering work in 1875 to its current status as a cornerstone of human neuroimaging. The chapter discusses how EEG captures the electrical signals generated by synchronous activity of pyramidal neurons arranged in open fields perpendicular to the cortical surface. It examines the technical evolution of recording systems, from basic silver-chloride electrodes to modern active electrode arrays with built-in amplification, and explains the standardized 10-20 electrode placement system that enables spatial mapping of brain activity. The chapter addresses the inverse problem that constrains EEG’s spatial resolution while highlighting its exceptional temporal precision for tracking neuronal events in millisecond timescales. Special attention is given to the characteristic oscillatory patterns in different frequency bands (alpha, beta, theta, delta, gamma) and their association with cognitive states ranging from deep sleep to focused attention. The chapter details practical considerations for obtaining clean recordings, including artifact reduction techniques and experimental design. By evaluating EEG’s strengths (temporal precision, direct measurement of neural activity, accessibility) alongside its limitations, the chapter positions EEG as an enduring, versatile tool for both clinical applications and cognitive neuroscience research despite technological advances in other imaging modalities.

This chapter develops the argument that land, in the form of the ground that warfare is fought on, gives land warfare certain unique characteristics, including its political significance, variability and resistant nature as a medium. These characteristics in turn shape the nature of the forces that fight upon land, making them complex, human-centric and persistent, and giving them the potential for the power of decision. Land warfare is complex: its prosecution requires navigating a wide array of competing trade-offs including those between manoeuvre and attrition, centralisation and decentralisation, and attack and defence. Land power, however, is composed of much more than land warfare, and joint and multi-domain capabilities make a vital contribution.

This chapter examines intracranial electroencephalography (iEEG), a rare but powerful technique offering unparalleled insights into human brain function by recording electrical activity directly from the brain’s surface. It traces iEEG’s development from pioneering work by Penfield and Jasper in the 1950s to modern applications with up to 1,024 recording channels. The chapter outlines the two primary surgical approaches, stereo EEG with depth electrodes and electrocorticography with surface grids, and explains how these techniques achieve both high temporal (millisecond) and spatial (millimeter) resolution by bypassing the signal-dampening effects of skull and scalp. Particular attention is given to high-gamma-power signals (70–200 Hz), which reflect neuronal firing with exceptional signal-to-noise ratios. The chapter addresses methodological considerations including electrode localization, signal processing, and data interpretation challenges unique to recording from epilepsy patients. It balances discussion of iEEG’s remarkable advantages, such as direct access to neuronal activity across cortical layers and network nodes along with its limitations, including restricted accessibility, sparse sampling, and the clinical constraints that dictate electrode placement. The ethical framework governing this invasive research methodology is emphasized throughout.

This chapter examines concepts and theories associated with naval warfare and maritime strategy. It begins with a discussion of the unique nature of the maritime operating environment before exploring the idea that navies have particular attributes or characteristics. It introduces the key principles of classic maritime strategy before exploring alternative approaches often employed by those facing an enemy stronger at sea. Concepts addressed include command of the sea, sea control and denial, fleet-in-being, blockade and guerre de course. These are explored with reference to relevant theories, to contemporary commentators and to current naval doctrine and maritime strategy.