Out of curiosity, can you point out where there is a shimmer of daylight between any single real Republican candidate (this precludes RonPaul (yes I realize it is two words but it's kinda like AlGore)) and the Bush Administration on Iraq?
I'm merely speaking the truth on this one.
Anyway, you would have to narrow your question to specific issues as far as Republicans being leaders. Bush hasn't led the country in a single positive direction since at least early 2002. I suppose the fellow at the state department, the guy in charge of far east affairs i believe it is, is a leader. He got a decent deal with the North Koreans on the nuclear issue. Of course we're no better or than under the Clinton Agreed Framework and in some real substantive ways we are worse off, but it took leadership to get done what he got done, particularly in the face of the Cheneyists in charge. I'm not sure his political affiliation, but he is certainly a leader.