Excuse me? Are terrorists no longer terrorists if their excuse is Islam?
Here's the thing: don't confuse the method of imposing political and physical change upon one's culture with the reason for doing so.
Terrorism is: the unlawful use of force and violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives.
"Terrorism" as a political tool, was first clearly identified during the 'Reign of Terror,' during the French Revolution...and those terrorists were mostly atheist. There have been Irish Catholic terrorists, Protestant Irish terrorists, communist revolutionary terrorists, all sorts. What unites them is their methods...but their MOTIVES differed hugely.
.....and when it comes right down to it, terrorism as a political tool WORKS. It changes society; look at what the WTC attacks did to us! I remember flying before 9/11. I've only flown once since then, and I probably won't fly again. I had to go through a security procedure that was unreal...middle aged me getting taken aside and given special 'pat downs' and inspections because my fake knee set off the metal detector. Now that I have TWO fake knees and a titanium rod in my arm, I really get the security people nervous.
My girls fly all the time....and EVERY time they spend at least twice as much time in the security line as they do on the actual flight...and they are only flying from LAX to SLC. The world has changed, and terrorists did it.
So terrorism works. Since we can't argue that terrorism isn't effective, we can only work with the motives FOR it....and they differ from one another as much as chalk differs from cheese. So it doesn't work to say 'terrorism is bad.' Of course it is. What we have to do is target why people are USING it.