Comparing the Soviet intervention in Afghanistan with the US intervention in Vietnam.

To claim that the US entered the Vietnam War "in good faith" requires stretching that concept so far that in includes lying at every level, including the false "Gulf of Tonkin incident" in which North Vietnamese vessels supposedly made a feeble and useless attack against US navy vessels. It never happened — it was a lie told by the US military to the American people and the US Congress.

The main US motive for sending troops to Vietnam was to avoid a humiliating defeat. This is the international relations version of the "sunk costs" fallacy: "We've spent so much political capital on that fight that we can't afford to lose now." For a great power fighting a weaker country, that is a recipe for endless war.

The US intervention in Afghanistan follows the same pattern, except that Obama failed to do what Nixon and Gorbachev managed to do.