In 2008, Najibullah Zazi, an Afghan American, traveled to Pakistan, where he received training in bomb making and agreed to undertake a “martyrdom operation” inside the United States. Zazi was arrested the following year and confessed to planning to detonate a bomb in the New York City subway. In December 2009, five Americans from Alexandria, Virginia—who were in contact with an al-Qaeda facilitator near the Afghanistan-Pakistan border—were arrested in Pakistan and later convicted on terrorism charges. They had been radicalized in the United States and went to Pakistan for training and operational guidance. Finally, in May 2010, Faisal Shahzad attempted to detonate an improvised explosive device in Times Square in New York City after being trained along the border by bomb makers from the Pakistani Taliban.

This pattern demonstrates that the situation now is vastly different from that of the early nineteenth century. Actors in Afghanistan and Pakistan can directly threaten American and European homelands, an unthinkable prospect in the 1800s. As a result, the risks of a complete withdrawal like the one the British orchestrated in 1842 would be far greater.

A second erroneous parallel is to compare the despised Afghan leader Shah Shuja with today’s president, Hamid Karzai. Preston writes that early British successes “led them into an open-ended commitment to a ruler whom they had not chosen well and, when they realized this, hesitated to replace or ‘guide’ sufficiently.” While this was certainly true of Shah Shuja, the situation with Karzai is different. Karzai’s tenure has, of course, been laced with problems. His government is corrupt (as is the Taliban). He has been plagued by indecisiveness and wild mood swings. And he exerts little control outside the capital.

Yet there are two major differences between Shuja and Karzai. First, Karzai was elected to office; Shuja was unabashedly installed by the British. Karzai won the 2004 presidential elections with 55 percent of the vote; the runner-up, Tajik leader Yunus Qanuni, won only 16 percent. The 2009 presidential elections were marred by concerns about ballot stuffing, intimidation and other electoral fraud. I was living in Kabul at the time and found the evidence of corruption incontrovertible, though it occurred with other candidates as well. Still, preelection polls found Hamid Karzai leading his nearest rival, Abdullah Abdullah, by a wide margin.

Second, opinion polls today give us a good way to gauge popular support. Assuming a healthy margin of error with polling in a war-torn country, polls still show widespread support for Karzai. A 2010 Washington Post poll found that his government enjoyed a 62 percent approval rating, while Karzai was viewed positively by 82 percent of the population—nearly double that of the U.S. president. In 2011, 46 percent of Afghans believed their country was going in the right direction, up slightly from 44 percent in 2006, according to the Asia Foundation. When asked to assess the way the national government was carrying out its responsibilities, nearly three-quarters of respondents in 2011 gave a positive assessment.

A final error would be to compare the Taliban with the widespread insurgency that rose up against the British. By early 1842, the British faced a massive, populist revolt inside Afghanistan spearheaded by Ghilzai and Durrani Pashtuns. Today, the Taliban, whose command-and-control node is in Pakistan, is not a widely popular movement. When asked who they would rather have ruling Afghanistan today, 86 percent of Afghans said the Karzai government and only 9 percent chose the Taliban, according to a December 2010 poll by the Washington Post and other news organizations. When asked who posed the biggest danger to the country, 64 percent of respondents said the Taliban, up from 41 percent in 2005.

It’s not difficult to see why the Taliban is unpopular. Its ideology, which is based on an extreme interpretation of Deobandi Islam, is opposed by most Afghans. In the 1990s, the Taliban closed cinemas and banned music, along with almost every other conceivable kind of entertainment. Most Afghans don’t subscribe to their religious zealotry, which is so extreme that the founders of Deobandism wouldn’t recognize it.

DESPITE THESE differences, there remain some valid lessons from the First Anglo-Afghan War. One of the most important is the fiction of a strong, central Afghan state. “Instead of being a united kingdom under a strong ruler,” Preston presciently writes in The Dark Defile, “Afghanistan was—even when at its most unified—a loose grouping of semiautonomous tribes, some speaking different languages and looking physically different from their neighbors.” This remains true today. Social structures have evolved over the past few decades because of war, droughts, migration patterns, sedentarization and other factors. But power remains local in rural areas, where the insurgency is largely being fought.

Pashtuns have long based identity on a nested set of clans and lineages that stem from a common ancestor. In the absence of strong government institutions, descent groups help Pashtuns organize economic production, preserve political order and defend the group from outside threats. These bonds tend to be weaker in urban areas, where the central government’s control is stronger. The identity of many Pashtuns may shift depending on the context and include their tribe, subtribe, clan, family or village. Pashtunwali, the Pashtun code of behavior, shapes daily life through such concepts as badal (revenge), melmastia (hospitality), ghayrat (honor) and nanawati (sanctuary). Local councils, or jirgas, remain instrumental in decision making at the local level, rather than formal courts.

Preston makes clear that rural governance was similar during the nineteenth century, where “in each tribe the gathering of elders—the jirgha—played almost as important a role as the titular ruler.” In this environment, it is impossible to develop an effective counterinsurgency strategy without understanding Afghanistan’s social structure, especially its local nuances. Today’s insurgency is composed of a loose amalgam of the Taliban and other opposition groups, allied tribes, drug-trafficking and other illicit groups, local power brokers and state sponsors. How these groups come together varies considerably across villages, districts and provinces.

The British understanding of Afghanistan’s tribes, Preston argues, was negligible. It culminated in Macnaghten’s ill-informed decision to dock British payments to the Ghilzai tribes that controlled eastern Afghanistan, including the passes they would use on their shameful retreat. “Perhaps the biggest British miscalculation,” she writes, was “unilaterally to reduce some of the subsidies paid to Afghan tribal chiefs. Their economy measure was immediately followed by an Afghan rising.”

With a few exceptions, the United States and other NATO countries have largely failed to understand the local nature of power in Afghanistan. Many Western countries are characterized by strong state institutions in which power emanates from a central authority. But in a range of countries—such as Afghanistan—the central government has historically been limited. Top-down state-building strategies may have been appropriate for countries such as Japan and Germany after World War II, both of which had strong centralized state institutions. But they aren’t likely to work as well in countries such as Afghanistan where power is diffuse.

Since the Bonn agreement in December 2001, international efforts in Afghanistan have largely focused on top-down efforts to establish security by trying to strengthen central-government institutions. On the security front, this translated into building only Afghan National Police and Afghan National Army forces as the bulwark against Taliban and other insurgent groups. On the economic and development fronts, it translated into improving the central government’s ability to deliver services to the population. An effective strategy must include co-opting Afghanistan’s tribes and other communities.

A final lesson is the political reality of war. The British decision to withdraw from Afghanistan was made, in part, because of growing economic problems back home. As Preston notes in The Dark Defile, a series of poor harvests, a downturn in home demand for manufactures and rising government costs contributed to growing skepticism about the importance of Afghanistan. As Lord Auckland wrote to Macnaghten in 1841, British support for Afghanistan was more at risk “from financial than from military difficulties.” The parallels with today are unmistakable, where economic travails in Europe and the United States have forced policy makers to rethink the financial costs of the war.

THE FIRST Anglo-Afghan War left behind a cauldron of searing images that enshrined Afghanistan as a graveyard of empires. Lady Butler’s famous painting of Dr. William Brydon is symptomatic. It shows the paltry survivor alone, disheveled and clinging to life on a decrepit horse. On the horizon, the sun sets as Brydon leaves behind a parched Afghan landscape. The symbolism is unmistakable.

Fortunately, this perception is largely mythical. As anthropologist Thomas Barfield soberly reminds us, “while the popular press often repeats the claim that no conqueror, including such figures as Alexander the Great or Chinggis Khan, ever succeeded in subduing the country, this is untrue.” Many of these conquerors did in fact subjugate the country and occupy the territory. What is less clear, however, is whether today’s foreign powers will learn the wrong lessons from Afghanistan’s history.

A precipitous withdrawal from Afghanistan, as some in the West hope for, may have grossly unintended consequences, especially if it leads to a Pakistan-backed Taliban takeover of the country. Today’s Afghan insurgents, including the Haqqani network and the Taliban, continue to cooperate with al-Qaeda and the Pakistani Taliban, both of which have targeted the United States. A Taliban government in Afghanistan would almost certainly remain an ally of al-Qaeda and would likely provide a boost to Islamic extremism in the region.