Since 9/11, successful domestic terror plots like the Boston Marathon bombing have been rare exceptions.
Perhaps the most unusual thing about the Boston Marathon bombing is that it happened at all. While we've seen all manner of terrorist bomb plots since September 11—the Times Square bomber, the underwear bomber, even the guys who fantasized about destroying the Sears Tower—all have been thwarted by the FBI, the perpetrators' own bumbling, or both. If one or both of the suspects in last week's attack, Tamerlan and Dzhokhar Tsarnaev, were motivated by radical Islamic beliefs, then they will have the dubious distinction of being the first jihadists to have set off a bomb on American soil since the 1993 World Trade Center bombing.
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