If we're picking mental states (properly held by individuals and not nations), then why not ignorance? Hubris comes from a misplaced understanding of American military strength - paranoia from a misplaced understanding of the intentions and capabilities of other nations. The litany of American military action abroad (and sadly, also at home) in the 21st century seems to be based entirely around swift triumphs and confused retreats - security forces too ignorant to see the buildup of al Qaeda to 9/11, an intelligence apparatus unable to pin down the location of senior AQ leaders, and again unable to pin down the exact status of Ba'ath run Iraq's nuclear, biological and chemical weapons programs, a military machine sublimely unaware of the building insurgency against them and even less aware of how to conduct itself against an enemy that refuses to commit to fire and maneuver warfare, etc.