This essay seeks to answer the question of what obligations intervening states have and why the US/NATO intervention in Afghanistan failed. With Afghanistan as a case study, it will attempt to illuminate the responsibilities and objectives of democratic intervening states in general. While it is too late for any near-term realistic hope of a just peace in Afghanistan, future efforts to create a democratic peace between nations should be built not only on humility about the intervenor’s knowledge of foreign peoples and cultures but a deeper understanding of democracy and peace between democracies. Given the ongoing need for asylum and the existence of the Afghani diaspora, it is not too late to learn from the people of Afghanistan as to how to proceed and honor our obligations. The reason why the US government and other NATO intervenors failed to achieve their desired outcome, a just and sustainable peace, is because collectively we not only had an institutionally weak knowledge of Afghanistan and Pakistan, we also had a poor understanding of democracy and peace between democracies. We were not just ignorant; we did not care to learn. This weakness, the misapprehension of democracy as more of a confidently perfected and exportable legal construct and not a humble ethical restriction on laws and knowledge, doomed our path to a just and sustainable peace. This misunderstanding about democracy, a misunderstanding that deepened at the height of American power, is important to correct if we are to achieve solidarity between democracies, and to intervene and choose not to intervene successfully in the future. A humbler approach to democracy-promotion, not an abandonment of it, would have had a higher likelihood of success over the past 20 years, and would still serve us better today in our relations with Afghanistan, Pakistan, and other governments and peoples.