If GWB had made the enemy fear our wrath, we would not have Iran & Syria actively and pretty much openly sticking it to us in Iraq. The Norks would be much more amenable to reason, as well.
For a small moment in 2003, there was fear, as shown by Kadafi losing his nerve & taste for WMD. After that, not so much.
longeye's second paragraph naturally follows the first. Not being able to go after domestic political opponents hammer & tongs (politically speaking) has led to external, existential enemies not fearing us.