As for not negotiating with brutal dictators, I've never been much interested in philosophical or ideological distinctions in argumentation. If it can't deal with reality, it can't deal. Period.

Find me any right-winger anywhere who will swear that he would not be willing to so negotiate if he believed that the price of armed conflict was unacceptable and that the national security interest (or even massive amounts of wealth) were at stake.

In other words, any ideological point in argumentation is pointless rhetoric if even its most fervent adherents, in certain contexts, would be more than eager to make massive exceptions.