Why did the United States lose the war in Afghanistan? Only a repeated habit of decision-making explains consistent strategic miscalculation. Policymakers in every administration prioritized counterterrorism – a comparatively simple, easily defined, “realistic,” concrete mission. They subordinated broader, more ambiguous, harder-to-define, morally aspirational, long-term goals, such as counterinsurgency and nation building. Policymakers did so even though – as repeated strategy reviews showed – the Taliban and al-Qaida were linked; success in the war against either depended on success in both; and counterinsurgency and nation building were necessary, alongside counterterrorism operations, to achieve the larger goal of al-Qaida’s defeat. These policies became embedded in the US bureaucracy, ensuring the bureaucracy kept implementing bad strategy on autopilot even when policymakers and repeated strategy reviews highlighted the problem.

The Taliban insurgency happened because they enjoyed a permissive environment: safe haven in Pakistan, state failure in Afghanistan, and an America increasingly focused on Iraq. In turn, most of those had common roots in the Bush administration’s decisions in 2001: to define the conflict as a “War on Terror” best waged with a light footprint and to conflate the Taliban and al-Qaida. Some of those decisions made sense in 2001, but none of them bore scrutiny as the situation in Afghanistan changed, and the Bush administration failed to adapt quickly enough.

Did the surge work? The surge had a major impact on the military situation, reversing the Taliban’s momentum and rapidly growing the Afghan army. Yet it seems equally clear that, by the beginning of the withdrawal in July 2011 – or even by the transition in 2014 – Afghan governance had not improved enough and there was no self-sustaining psychological dynamic of growing optimism and confidence. Importantly, the military surge cannot be evaluated apart from either the civilian surge or the withdrawal timetable because they were components of a single strategy. The civilian surge largely failed, replicating many of the same problems the Bush administration had seen when it tried to ramp up assistance for governance and reconstruction. But even more consequentially, the timetable – the most distinctive aspect of the Obama administration’s war – drove so much of the implementation and the decision-making as to become the controlling dynamic of the war. Together, the timetable and the civilian failure squandered whatever military gains the surge accomplished. By 2011, the insurgency had lost momentum, but the Afghan government was no closer to victory.

The case for more aid to Afghanistan slowly gained ground from late 2002. The Accelerating Success initiative, coupled with the Bonn Process and a new Afghan Constitution, began to move reconstruction efforts in the right direction. A new reconciliation program recognized the need for a settlement with the Taliban. But enduring challenges from recalcitrant warlords, international donors, inflexible diplomacy, and a sclerotic bureaucracy counteracted whatever progress was achieved from 2003 to 2005.

The 2009 strategy review resulted in the most consequential decisions of the war. While scholars and historians have typically focused on the surge of 30,000 additional troops, the administration’s strategy was not simply to add more troops. Obama rejected the logic that to defeat al-Qaida required defeating the Taliban and made an explicit decision not to seek the Taliban’s defeat – but he also chose to escalate the war against them anyway. Instead, Obama adopted a vague goal of “reversing their momentum,” while training Afghan security forces. That was muddled enough, but he undermined even those goals by adopting a public withdrawal timetable for US troops and failing to coordinate the surge with reconstruction and diplomatic efforts. Coupled with internal miscommunications, tensions with the military, and a growing attitude of pessimism, the changes introduced in the December 2009 strategy hamstrung the surge and set the course for the rest of Obama’s presidency.

As the surge petered out, the Obama administration had to decide what came next. On paper, Afghan security forces were supposed to take the lead for security throughout Afghanistan by 2014. But as the military surged and withdrew, a faction within the administration began to push for another option. Those who doubted that military progress could be sustained argued that the only plausible route to ending the war was through negotiations with the Taliban. Unfortunately, the Obama administration’s negotiations with the Taliban were undermined by battlefield realities, bureaucratic pathologies, and, above all, the withdrawal of US forces from Afghanistan.

For its first eighteen months, the Trump administration steered a surprisingly defensible course in Afghanistan, thanks to many of Trump’s appointees who worked to preserve something of America’s interests intact within the confines of Trump’s desire to reduce American commitments overseas. They were squeezed from two sides: on the one hand, the frustrating results of the Obama administration’s various strategies – surge, drawdown, and negotiations – seemed (wrongly) to prove their futility. On the other hand, virtually no one was convinced that Trump’s demand to get out fully and immediately was a good idea. They wanted to stay, but it was unclear what kind of posture, mission, or strategy would be more effective than what Obama had tried.

Having accomplished its immediate objectives, the spring of 2002 was an ideal moment for the administration to pause and reassess its strategy, goals, and purpose in Afghanistan. Rather than grapple with the newfound complexity, a sense of inertia, drift, and inattention took over. There was, of course, a sense of urgency and a serious debate starting in the spring of 2002, but it was not about Afghanistan. As the year wore on, the administration became almost wholly consumed with preparations for the war in Iraq. Counterintuitively, the drift and inattention could occasionally work to Afghanistan’s benefit. The Bonn Process unfolded as planned and was widely seen as a success with only loose oversight by policymakers in DC and more leadership from the UN. Unfortunately, Bonn would prove to be the easy part. While the political process unfolded, the international community tried, and, absent American leadership, failed to mount the most ambitious reconstruction and stabilization operation since World War II.

Trump’s newly empowered foreign policy led to the Doha agreement with the Taliban and America’s final defeat in Afghanistan. The Taliban’s principal demand and the central element of the eventual Doha agreement was the full withdrawal of US forces from Afghanistan. It was hardly something the Taliban needed to demand because Trump was demanding it too. Trump was not inclined to enforce the agreement anyway. Trump campaigned on getting out of Afghanistan and repeatedly and publicly announced his intent to withdraw, which undermined negotiations just as much as Obama’s timetable had done.

In late 2006 and early 2007, the Bush administration recognized that Afghanistan was deteriorating sharply and undertook a series of strategy reviews. The reviews led to more troops and a new counterinsurgency strategy with attention to training Afghan security forces and improving governance, reconstruction, and counternarcotics. As in 2003, the new approach ran into the buzzsaw of bureaucracy, the fog and friction of war, unanticipated challenges, and, now, a far stronger and more resilient enemy. The problems with the American war effort in 2007 and 2008 were less problems of strategy than of implementation. Having blundered badly in the early years and created huge problems for itself, the American effort was now playing catch up, trying to adjust rapidly to a deteriorating situation.

Some common themes emerge from these lessons about strategy and bureaucracy. The statesman and strategist also need wisdom to take the long view, prudence to discern what is practical, persistence and fortitude in implementation, courage to overcome groupthink and pride and bureaucratic resistance, temperance and humility to toil in unglamorous details. Above all the strategist must have a passion to pursue justice and peace. Statesmen and stateswomen need wisdom, courage, temperance, and justice. If that is true, such timeless principles do not apply only to the individual policymaker. They apply to the nation we serve. American foreign policy should be characterized by wisdom, courage, temperance, and justice; our role in the world should serve those principles. Our grand strategy should take the long view, be practical and aware of our limits yet also courageous and visionary, fearless and uncompromising in the face of obstacles. Above all it must aim at justice – which means it must serve American interests, but it must do so with an awareness of how our interests are entwined with others.

The Bush administration faced three major strategic choices between September 11 and October 7, when the military campaign started: how to define the war, what to do about the Taliban, and what kind of military footprint to deploy. The administration chose to frame the conflict as a War on Terror, to treat the Taliban as of secondary importance, and to adopt a light footprint. The first choice – to declare a War on Terror – has been the subject of ample and justified criticism, then and now. The latter two choices made more sense at the time, and the Taliban’s fall from power two months later, on December 7, seemed to vindicate the administration’s impressive improvisation. But the sense of vindication also numbed the administration to the need to adapt as circumstances changed.