I agree. By appealing to the isolationist streak in American culture (both personal and political), you could help to move invading and/or attacking Iran off the radar.
I would say that most Americans do not like the idea of empire, but there was enough time between Vietnam and Iraq for people to forget about a protracted struggle, and with no mandatory draft the war is more abstract than if people's lives were suddenly and rudely interrupted. Bring back a draft and the war would be over in a minute and Iran would be off the table.
Brian