I am flagging Daniel Kuehn’s post for this quotation from a paper by David Henderson:

“In his testimony before the commission, Mr. Westmoreland said he did not want to command an army of mercenaries. Mr. Friedman interrupted, "General, would you rather command an army of slaves?” Mr. Westmoreland replied, “I don’t like to hear our patriotic draftees referred to as slaves.” Mr. Friedman then retorted, “I don’t like to hear our patriotic volunteers referred to as mercenaries. If they are mercenaries, then I, sir, am a mercenary professor, and you, sir, are a mercenary general; we are served by mercenary physicians, we use a mercenary lawyer, and we get our meat from a mercenary butcher.”“