If the United States invades Iraq, bombs Hezbollah and conducts strikes on Syria and Iran, this war will metastasize into a two-continent war from Algeria to Afghanistan, with the United States and Israel alone against a half-dozen Arab and Muslim states. The first casualties would be the moderate Arabs Egypt, Jordan, Saudi Arabia, the Gulf states who were our Cold War and Gulf War allies.
The war Netanyahu and the neo cons want, with the United States and Israel fighting all of the radical Islamic states, is the war bin Laden wants, the war his murderers hoped to ignite when they sent those airliners into the World Trade Center and the Pentagon.
Buchanan could have made this argument: that unless Osama terrorists move to a particualr country, or receives a substantial suport from a particular country, we shouldn't attack that country in the context of this war. That would have been a valid comment, and I would agree with it.