"If you had told me in 1975, when the Vietnam War finally ended some 34
years after Luce wrote that essay and 28 years before the U.S. invaded
Iraq that, in 1979, Washington would become involved in a decade-long war in Afghanistan, I would have been stunned."
Well, Tom, you are not much of an observer.
After 1975, the war aginst Vietnam continued by proxy in Cambodia with USAian support for the Khmer Rouge through sending aid to their camps inside the Thai border, with China sending arms to the Khmer Rouge (having previously invaded Vietnam), and Thailand providing comfort to Pol Pot and the Khmer Rouge . The USA also supported the genocidal Khmer Rouge at the UN until at least the mid 1980s. As revealed in Parliament, the British had also done their bit in sending members of the British SAS to Cambodia to train the Khmer Rouge in laying land-mines. At that time the Vietnamese army was occupying Cambodia, having invaded in 1978 following three years of cross-border attacks by the Khmer Rouge since 1975. Vietnam liberated Cambodia.
The USAian involvement in Afghanistan began in 1979, Tom, when the USA started its sponsorship of the mujahiddeen terrorsts against a USSR-friendly government. The USA continued such sponsorship until at least the Russians had been driven out of Afghanistan.
Just to bring you up-to-date with world affairs, Tom, since you are so surprised by events." Brother Enemy" by Nayan Chanda, written some years ago, will inform you in detail about the third Vietnam war; John Pilger and Robert Fisk have written about affairs in Afghanistan.