There is little evidence of this in Islamic terrorism.
Al Queda did a number of dry runs prior to 9/11. The scale of today’s attack was quite small, but its repercussions large. I suspect that Al Queda/Muslim Brotherhood operatives in the U.S. homeland were ordered to monitor security reactions throughout the US (NY/DC subways and airports, for instance), probing for weaknesses for a future *larger* scale attack.
If I had any money left after five years of Obama, I’d bet that Al Queda/Muslim Brotherhood is currently planning a large-scale attack on the homeland in the near future. Boston Marathon might be a good dry-run op for July 4 on the National Mall, for example.
If this really was the work of AQ/MB, and not some isolated wing-nut, then expect a much larger, coordinated, multi-city attack on the homeland in the near future.
9/11 occured on the anniversary of the Battle of Vienna, which marked the end of Islamic expansion into Europe