This book uses the study of the recent past to illuminate the future. More specifically, it examines the lessons of recent wars as a way of understanding continuity and change in the character and conduct of war.

This chapter examines the role that historical lessons play in thinking about the conduct of warfare. First, in order to establish context, the debate over the use of history for "lessons learned" is sketched with the aim of highlighting the differences between the applied and pure schools of thought that exist on the subject. Second, the chapter argues that the most effective way to use history in the study of war is to develop a contemporary approach to the subject. Third, and finally, it is argued that, in the profession of arms, the use of history tends to flourish when historians embrace an interdisciplinary perspective and when they concern themselves with examining the interconnections between the past, the present, and—most especially—the future of war.

This chapter examines the challenges that militaries have had in learning lessons from war, with particular focus on the U.S. armed forces in the twentieth century.

The Iraq War is replete with lessons that have particular relevance to the future of the U.S. military. Indeed, given the dramatic rise and subsequent fall of the Islamic State, the effects of the Iraq War continue to resonate to this day. The U.S. Army has had the opportunity in recent years to put into practice what it learned from the war in Iraq. Circumstances may have changed at the margins, but the root causes of the conflict, as well as the solutions to it, have remained constant.

This chapter analyses key dynamics of the British war in Iraq and identifies lessons that may be relevant to the future U.S. Army. It is based on the evidence gathered writing the British Army's final analysis of stabilization operations in Iraq, the United Kingdom's Iraq Inquiry, both the extensive testimony and the inquiry's assessment, and on much material published in the United Kingdom and the United States since the war.

This chapter focuses on the 2003 invasion of Iraq. In all but the most exceptional, fleeting, or tactical circumstances, the outcome of the initial military objective (to unseat the regime) was never in doubt. Despite the fact that Iraq's armed forces were large, reasonably equipped, and sited on moderately defensible terrain, they were with few exceptions poorly led, unmotivated, undertrained, and completely exposed to the asymmetric effects of U.S. air power. In order to develop a more complete case study, the chapter describes the strategic environment from the Iraqi perspective. It outlines the 2003 coalition invasion of Iraq from the perspective of senior Iraqi military leaders and commanders. These perspectives widen and offer "curious incidents" worth exploring as either alternative cause-and-effect explanations for what did occur or as points of departure to consider the implications of what did not occur.

This chapter examines America's war in Afghanistan. It describes the two main strategies that were employed, explains why the U.S. effort came up short, and examines what Afghanistan means for the U.S. military, particularly whether it shows that the military is incapable of winning irregular wars. The chapter is divided into four main sections: first, the initial intervention and the fateful mistakes of the war's early years (2001–2005); second, the return of the Taliban in 2006 and U.S. and allied attempts to hold them back; third, the surge of 2009 and the operations that followed in 2010 and 2011; and, fourth, the slow U.S. withdrawal from 2012 to 2014. The final conclusion analyzes why U.S. efforts never succeeded and explains Afghanistan's significance for the US military.

Britain's war in Afghanistan from 2001 to 2014 covered four overarching operations—Veritas, Fingal, Jacana, and Herrick. Operation Veritas saw Britain deploy cruise-missile-firing nuclear submarines and refueling and reconnaissance aircraft from October to December 2001, to support the U.S.-led war on al-Qaeda and the Taliban in Afghanistan. The British land component to this phase of the war came from special forces with up to three hundred troops deployed; of these, a third operated behind enemy lines in southern Afghanistan conducting strike missions against Taliban targets.

Security force assistance was a major pillar of U.S. strategy in Afghanistan, so much so that local security forces were often spoken of as "our ticket home" or "our exit strategy." The effort to raise, train, equip, field, and advise army and police forces eventually became the center of gravity. Yet initially, the effort was ad hoc, under resourced, and complicated by internal bureaucratic struggles in Washington and by corruption and mismanagement within the Afghan government. This chapter will deal in turn with the army, national police, and village police programs to include some discussion of the Ministries of Defense and Interior. It will focus on the problems encountered. However, one remarkable success cannot be denied. Starting from scratch, the coalition raised, trained, and equipped an Afghan security force of over three hundred and fifty thousand personnel.

Among the many reasons that help explain the unfortunate outcome in Afghanistan are institutional shortcomings that compromised performance. The basic argument is that the U.S. interagency process, civil-military relations, and bureaucratic politics all worked against success, despite highly professional, even preeminent military, intelligence, diplomatic, development, and other organizations.

In May 2009, the Sri Lankan armed forces decisively defeated the Liberation Tigers of Tamil Eelam (LTTE) insurgent organization after three years (2006–2009) of grueling warfare. This was the final phase of an almost three-decade long war that began in 1983. Throughout much of the course of this ethno-separatist insurgency the LTTE displayed a high level of proficiency spanning the continuum in the war against the government of Sri Lanka. This "hybrid" approach to warfare combined ways of war including a wide array of technologies and innovative operational art and tactics that helped the Tamil Tigers defeat or fight the Sri Lankan military to a standstill in the first three phases of the war. Between 2006 and 2009, the Sri Lankan armed forces got the better of the LTTE and inflicted a series of devastating defeats on the once feared insurgent organization.

The purpose of this chapter is to provide lessons for consideration for training, preparing, planning, and execution of future operations in support of a friend, partner, or ally to advise and assist in their internal defense and development programs so that they can defend themselves against lawlessness, subversion, insurgency, and terrorism. This chapter will examine U.S. strategy and operations through the lens of special warfare. After providing an overview of the complex threats, we will look at the pre-9/11 actions that provide important context, then the actions taken after 9/11; conduct an analysis of the mission and the campaign design; and then describe selected vignettes to highlight key lessons learned.

A number of lessons from the 2008 war between Russia and Georgia are relevant. These center on Russia's statecraft, its practices that have now come to be termed "hybrid war." They also relate to decision making in Russia, and the mix of strategic thinking and opportunism that underlies Russian policies.

Four issues have driven Russian General Staff thinking during the post-Soviet period. The first was the realization that the "noncontact" and "netcentric" style of warfare being realized by the American armed forces was obviating the style of warfare the General Staff had developed since the height of World War II. Second, concerns over weapons of "new physical principles" and how they might enable the so-called "American Conventional Prompt Global Strike" strategy gave rise to a near-term solution dependent upon the development of "new generation" nuclear warheads and a search for enhanced survivability through greater mobility. Third, these technical challenges were further compounded by the loss of strategic depth, requiring changes in the application of command-and-control principles to the conduct of operations. Fourth, a net assessment of the overall military-technical situation led to a search for asymmetric thinking in compensating for inherent inferiorities.

The Israeli government convened a series of boards and commissions in 2006, following the Second Lebanon War, to analyze the conflict; identify strengths and weaknesses, successes and failures; and develop ways to rapidly improve performance by incorporating these lessons into the Israeli Defense Forces.

This chapter will argue that many Colombian regions have witnessed a triumph of COIN (counterinsurgency) tactics in a strategic vacuum of government presence. Critics complain that Colombia's rehabilitation is, at best, incomplete. While security in the major cities and roads may have been consolidated, the conflict has simply been pushed to the periphery, where the government retains a fragmented and at times hostile relationship with its citizens.

The conclusion summarizes the main themes of the book.