Cheney did the same thing immediately prior to the Gulf War. Just like back then, some of our allies are getting cold feet and need a talking to, to build a little backbone. Drudge has post that the first attacks were cancelled at last minute because Saudi Arabia, Oman, and Uzbekistan had cold feet and told us we couldnt use their bases.
I am well aware that Dick Cheney went to the area prior to the execution of Desert Storm but it occurred at a time when our forces were already positioned. It was more of a morale factor for our troops than anything else.
If it comes down to our so-called allies requiring a face-to-face pep talk by SECDEF personally, then I say "screw em' and the camels they rode in on". Let the Secretary of State play the role as diplomat and let SECDEF play the role of enforcer.