Unfortunately, few of us have much experience dealing with the threat of terrorism, so its been difficult to get facts about how we should respond.
主干：...few...have much experience..., so its been difficult to get...
1. so是个并列连词，连接两个分句，表示因果关系。
2. 前一个分句的谓语用了have experience doing...句型，表示有做......的经验。
3. 后一个分句用了it is+形容词+不定式句型，it是形式主语，真正的主语是不定式to get facts...;句末的about...是介词短语作定语修饰facts，about的宾语是个how引导的名词性从句。
译文：不幸的是，我们中很少有人对付恐怖主义威胁的经理，因此很难得到我们应该如何应对恐怖威胁的事实。