How the US military actually conducts its invasions and wars bears no resemblance to the propaganda. From Fred Reed at unz.com:
Or Gilbert and Sullivan Come to Afghanistan, Depending on Your Perspective
Forty-six years ago in a previous comedy I was in Saigon, recently having been evacuated from Phnom Penh in an Air America—CIA—Caribou carrying, in addition to me, several ARVN junior officers and perhaps a dozen BUFEs (Big Ugly Fucking Elephants, the ceramic pachyderms much beloved of GIs). America had already embarked on its currently standard policy of forcing small countries into wars and then leaving them in the lurch. In Cambodia this led to the reign of Pol Pot, the ghastly torture operation at Toul Sleng, and a million or so dead. In the unending fight for democracy, casualties are inevitable.
At the time Saigon was tense because Ban Me Thuot had fallen and the NVA roared down Route One toward Saigon. To anyone with the brains of a doorknob, the American adventure in Vietnam was coming to an end, but the embassy was studiedly unconcerned. Embassies do not have the brains of a doorknob, but are keenly aware of public relations. Acknowledging the inescapable is not their way. As usual, Washington would rather lie than breathe, and did. As in Cambodia, so in Nam, and so later in Afghanistan.
Apparently a genius at State realized that a lot of gringo expats lived in Nam—the number six thousand comes to mind, but may be wrong—and that six thousand hostages taken when Saigon fell would be bad PR. So the embassy in Kabul—Saigon, I meant to say, Saigon—quietly announced that expats could fly out on military aircraft from Ton Son Nhut. They didn’t, or at least many didn’t. The NVA continued its rush toward Saigon.