I don't understand why terrorists would expect this to work this time. It hasnt worked so far and the Phillipines have their own share of beheadings at home.
Personally I think the terror networks are running out of two digit IQ heavyweights.
They are sloppy but they have managed some small victories such as influencing the Spanish elections. And they probably monitor the sentiments here in the U.S. Of course when the first few beheadings occured I heard some say we should just pull out-that is exactly what we should not do.