There's an obvious takeaway about the pitfalls of nation-building, but there's also a deeper revelation about the limits of liberalism itself.The inability to establish an enduring, stable democracy in Afghanistan after spending 20 years, trillions of dollars, and thousands of American lives delivered a decisive blow to the catechism of neoconservatism. But it also revealed blind spots and misplaced assumptions of modern Western liberalism.Liberalism — not the misused synonym for leftism but the political, social, and moral philosophy arising out of the 18th-century Enlightenment — produced many great breakthroughs for human thriving and liberty, including the American experiment itself. Its...