Sentence:  But in 1992, Bissell still maintained, "Lumumba and Sukarno were two of the worst people in public life I've ever heard of. They were <WSD>mad dogs</WSD>. Castro I saw not as a <WSD>mad dog</WSD> but as a purposeful antagonist. I believed that they were dangerous to the United States. There was a widespread belief that societies in the noncommunist world were exceedingly fragile, susceptible to being destroyed by these demagogues." 
Meaning of the word marked with <WSD> tags:  Someone who is aggressive and fanatical; an aggressor who cannot be reasoned with.