Lots of senile old Paleos cannot grasp the concept that you defeat an enemy by killing him, not ignoring him. The really sad thing is the author is the one mindlessly clinging to his ideology. Just another Dinaosur Conservative who is refusing to evolve to deal with the realities of a changing world. Author seems to find the post 9-11 world too emtionally painful to deal with so clings to his comfortable assumptions and false premises rather then deal with it.
Again, I think the main thesis: Bush is ideological as opposed to Buckley's definition which is that conservatism is anti-ideological. Of course, I don't agree with either, 100%, but it's worth pursuing.
If you want the weakest argument, though, WMD's would have to be it.