On October 7, 2001, with the twin towers still smoldering, US military forces entered Afghanistan with supreme confidence. President George W. Bush announced that US objectives were to “disrupt the use of Afghanistan as a terrorist base of operations and to attack the military capability of the Taliban regime.” The phrase “nation building” was not used.

Weeks later, with the Taliban effectively driven from power, NATO assembled a few dozen prominent Afghans in Germany. Their assignment was to draft a constitution and form a new government. Both were to be constructed upon Western democratic principles.

Determined not to repeat the mistakes of Viet Nam, the US incorporated social outreach, infrastructure building, and civil engagement into its plans. Over the next 20 years, the US spent more than $2 trillion funding not just military operations and the Afghan government, but also a broad spectrum of civil and educational projects.

Those evangelical and humanitarian priorities often conflicted with our stated objectives: hunting Osama Bin Laden, disrupting Al Qaeda’s terror networks, and degrading the Taliban. The mission creep that doomed the Afghan project was baked in from the outset.

Operation Enduring Freedom metastasized into an attempt to graft secular liberalism onto a culture dominated by grinding poverty, Islam, the opium trade, and the machinations of regional warlords.

The NATO occupation did unleash a civil awakening. The literacy rate increased from 8% in 2001 to 43%. School attendance by girls increased from 50,000 in 2001 to 3.2 million in 2013. The rate of child marriage was reduced. At least in urban areas, women were empowered to study, work, and participate more fully in public life.

There were also improvements in healthcare and living standards. Life expectancy increased from 56 to 64 years and maternal mortality was cut in half. For residents of major cities, access to clean water grew five-fold.

The original objectives of Enduring Freedom were met well before Bin Laden’s killing in 2011. The Taliban’s military reach was thoroughly degraded in the early phase of the conflict.

However, covert support from Pakistan made it impossible to remove the Taliban from the picture, so a political compromise proved elusive. Faced with deals that required ceding some control back to the Taliban, our nation-building instincts made it difficult to walk away.

The Taliban blitzkrieg return raises a thousand questions. The most intriguing is perhaps the most fundamental: can new customs ever take root if they are not compatible with local culture?

As burqas return to Kabul and Western sympathizers mob the airport, it is clear that the liberalism we nurtured will not endure without outside funding and protection. Many characteristics that defineAfghanistan and its culture are inherently hostile to secular liberalism.

For starters, Afghans have little engagement with nationhood. Most identify primarily with their home region and their tribal affiliation. The greatest unifying force in Afghanistan is not national identity. It is Islam.

Wahhabism, the Islamic fundamentalist movement popularized by Saudi-funded madrassas throughout the world, is ideologically hostile to both liberalism and secularism. The Taliban, whose name means “student” in the Pashto language, was birthed from those very madrassas.

Corruption and cronyism are also intrinsic to Afghanistan. In the absence of foreign interference, regional warlords historically dominated Afghan politics, fostering a culture of nepotism, cronyism, and extortion. From Hamid Karzai to Ashraf Ghani, recent leadership has perpetuated these flaws.

The US spent over $30 billion on Afghan reconstruction projects. A report by the US Special Inspector General concluded many were riddled with corruption. American dollars funded hospitals that were never used, schools that taught no students, power plants that failed, and bases the Afghan security forces quickly abandoned. Between 2008 and 2017, $15.5 billion in waste, fraud, and abuse was documented.

Opium is another defining characteristic of Afghanistan. The country produces an estimated 80- 90% of the world’s supply. A 2009 UN report pegged the annual heroin trade at $65 billion. Other studies indicate the poppy industry employs more than 3 million Afghans. Today the Taliban tax it, and opium is a core component of the economy.

The Taliban banned opium, back in 2000 when they were eager for foreign recognition of their sovereign legitimacy. The ban was unpopular, and after the occupation they reversed course. Subsequent propaganda described flooding the West with heroin as a form of “narco terrorism.”

The US spent $10 billion trying to curb the opium trade and made barely a dent. We also spent $24 billion to stimulate the legal economy. Afghanistan’s GDP doubled relative to 2007, but that didn’t produce a healthy economy. More than a quarter of the population is still unemployed.

Liberal democracies require a vibrant civil society, impartial law enforcement, and tolerance for diverse beliefs. Afghanistan’s history and culture stand opposed to all three. Evangelizing Western values was an unattainable, quixotic quest.