After introducing other dignitaries and before giving his defense of General David Petraeus and the Bush administration's strategy in Iraq, McCain handed a microphone to each of the seven soldiers — all wearing fatigues and berets — who introduced themselves by name, rank, and, in some cases, a description of their prior service elsewhere.

The Army personnel then stood alongside McCain in front of approximately 75 attendees. The campaign had advertised the midday event as a "barbecue," and served hot dogs, hamburgers, chips and soda.

"Thanks guys for being here," McCain said. We're honored by your presence and your service."

A Pentagon official did not dispute that the 2004 directive would apply in this instance.

"Department of Defense maintains a long-standing policy that DoD personnel acting in their official capacity may not be engaged in activities that associate DoD with any partisan political campaign or election, candidate, cause or issue," Lt. Col. Jonathan Withington wrote in a statement.