有关哲学有些词不大明白中文含意,

1.可以理解成society吗 --> no you can't,the author does not mean that.You can read the sentence as ...XXX mode of politics is a "politics of fear"..
2.sexual depravity要理解成性堕落/沦丧吧 --> ok.腐败 is a culture.堕落 is a personal behaviour.So the actual meaning has to be reviewed by the whole context of the writing.
3.the only true alternative to fear is terror --> read as ...the alternative to "fear" is "terror".