I think you should have checked the database, which you obviously didn't, before writing two long replies.
You see the decline after 2000 in the US and in Europe, which are the regions affected by Muslim terrorism (outside of Muslim countries, where this dynamic would not apply). You don't see it in Japan, Russia, India, China, or in Muslim countries. You don't see it in the world overall. This is entirely consistent with my hypothesis; your hypothesis that it is coincidence is the one that requires coincidence.
And, yes, when I write a post that says it's about America, it's going to be Americo-centric. I live in America. It's okay for me to talk about America.
Your replies bear little or no resemblance to what I've written. I never made a hypothesis of 'coincidence,' I never said you shouldn't talk about America, and overall I have to conclude that either I am writing unclearly, or you are misrepresenting me.
In either case, I am disinclined to continue such a conversation.
Yesterday I was using the Global Terrorism Database to check some suprisingly low figures on what percentage of terrorist acts are committed by Muslims. (Short answer: Worldwide since 2000, about 80%, rather than 0.4 - 6% as given in various sources.) But I found some odd patterns in the data for the United States. Look at this chart of terrorist acts in the US which meet GTD criteria I-III and are listed as "unambiguous":