Yglesias  points to George Will’s review  of Nixonland, noting Will’s complaint that Perlstein dismissively referred to ARVN as a “joke.” That must mean that George Will was a vehement, outspoken critic of Fred Thompson when he insultingly ignored  or belittled  the sacrifices of allied war dead in his regular stump speech routine (“This country has shed more blood for the liberty of other countries than all other countries put together”), right? That would be incorrect. As far as I can determine, Will never said anything about this, even though the Post ran a much-maligned and somewhat flawed critique  of this claim. So the rules are clear: repeatedly ignoring and belittling the sacrifice of British and Commonwealth forces (among others) in two wars to engage in national preening are fine, but making one passing remark about a South Vietnamese army that actually was pretty ineffective in defending its country is a terrible insult.
P.S. Other things in Will’s review are more worthwhile.