Good guys versus Bad guys.
White hats versus Black hats.
Anyone who deviates from this line of thinking is, in their opinion, wrong. Not just wrong, but doomed.
That's the Neo-con argument for Pre-Emptive warfare. Period.
Making a comparison between Radical Islam and Nazism is a dangerous one, mostly because they don't have much in common. Nazi Germany was a pervasive police state led by a sociopathic dictator who led a motley band of mafioso, knee-cap breakers, and assorted thugs into power. It was a well-oiled machine with a chillingly precise and uniform manner of conducting business.
By contrast, Radical Islam has no allegiance to a single state or a single philosophy. It's a movement that does not coalesce around any single nation or single manner of conducting business, regardless of what W and the rest of his followers would like you to believe. Fascism was certainly a potent threat in its day and age, but Mussolini, Hitler, and Franco played by different rules of conduct. What was true in 1939 is not true in 2008.
Comparing Fascism to Radical Islamic Terrorism is a lot like comparing apples to oranges. It just doesn't wash.
Radical Islam cannot be attacked by conventional tactics, because its membership cannot easily be defined. We're still arguing over why terrorism is created. The right has its own hypothesis. We on the left have our own.
By comparison, the reasons why the Nazis came to power are pretty much defined and agreed upon by historians. In short, the entire nation of Germany was in a state of depression and economic devastation so profound that it makes what we suffered in the Great Depression pale in comparison.
Radical Islam is comprised of a fringe element of determined followers, but it has no wholesale support among the greater community. The right peddles fear of the unknown very skillfully, as the right always will do. The right assumes that this threat will grow and spread until it infects the entire Middle East. We on the left believe differently.
The struggle we now face is that of trust versus fear and terrorism is just the latest variable in the ideological fight. Do you trust that we can negotiate with our enemies? Or, do you fear that doing so is not only dangerous, but will inevitably backfire?
Do you believe that radical Islam is like a cancerous growth that must be assaulted with massive doses of chemotherapy treatments, or do you concede that perhaps we had a hand in creating the mass division of cells in the first place?
That's where the argument has stalemated. The truth is somewhere in between.