The South Vietnamese would come to appreciate the insight.

So it is today with Aleppo, where savage reprisals against U.S.-backed rebels are taking place in that hellhole of human rights.

Yet, again, the wrong lessons are being drawn from the disaster.

According to The Washington Post, the bloodbath is a result of a U.S. failure to intervene more decisively in Syria's civil war: "Aleppo represents a meltdown of the West's moral and political will – and … a collapse of U.S. leadership.

"By refusing to intervene against the Assad regime's atrocities, or even to enforce the 'red line' he declared on the use of chemical weapons, President Obama created a vacuum that was filled by Vladimir Putin and Iran's Revolutionary Guard."