Wehner isn't speaking about "blowback" from foreigners (He wouldn't dare.) He's referring to the non-interventionist voices in the U.S. that have grown by leaps and bounds since Ron Paul's campaign. The American public waking up, and not remaining in a woozy stupor as the war machine tramples on, is the type of "blowback" that Neocons do understand.
http://www.lewrockwell.com/2013/09/chris-rossini/the-blowback-neocons-fear/