I wish I could give you a qualified answer. I can’t. The only thing I can think of is the attempted universal reach of Islam. If you can clear the planes, trains and other forms of transportation of any deterrent … and crap happens!
But, to postulate this idea reeks of conspiracy … and I’m not a conspiracy nut.
The only thing I’m willing to personally consider along these lines is Obama’s Islamic heritage.
Other than that, who knows?
;-)
It could be just the common thought of liberals, that if you defend against something you get more of it, force is futile.