Forty years after the defeat of the United States in Vietnam, the central lessons of that war remain unlearned. Even worse, the mistakes made and crimes committed in Vietnam have been repeated at great human, material, and strategic cost in a variety of subsequent national settings. The central unlearned lesson in Vietnam is that the collapse of the European colonial order fundamentally changed the effective balance of power in a variety of North/South conflict situations that reduce the agency of military superiority in a variety of ways.

What makes this change elusive is that it reflected developments that fall outside the policy parameters influential in the leadership circles of most governments for a cluster of reasons. Most fundamentally, governmental geopolitical calculations relating to world order continue to be based on attributing a decisive causal influence to relative military capabilities, an understanding at the core of “realist” thinking and behavior. Within this paradigm, military superiority is regarded as the main driver of conflict resolution, and the winners in wars are thought to reflect the advantages of hard-power differentials. The efficiency and rewards of military conquest in the colonial era vindicated this kind of realist thinking. Europe with its dominant military technology was able to control the political life and exploit the resources of populous countries throughout Asia, Africa, and Latin America with a minimum of expenditure and casualties, encountering manageable resistance, while reaping the rewards of empire. The outcomes of World War I and II further vindicated the wider orbit of the realist way of thinking and acting, with military superiority based on technological innovation, quantitative measures, and doctrinal adaptation to new circumstances of conflict receiving most of the credit for achieving political victories.

The Vietnam War was a dramatic and radical challenge to the realist consensus on how the world works, continuing a pattern already evident in nationalist victories in several earlier colonial wars, which were won – against expectations – by anti-colonial forces. Despite these illuminating results of colonial wars after World War II, the American defeat in Vietnam came as a shock. The candid acknowledgment of this defeat has been twisted out of recognition to this day by the interpretive spins placed upon the Vietnam experience by the American political establishment.