Don't rise to the bait. The principal problem for Moslems is internal. Their religion cannot compete easily with the modern world. Their young people are as attracted to American soap operas and movies as any other youth in the world. The Imams cannot compete. Change is sweeping through Moslem lands as fast or faster than it is through the West. The unease within Islam has spawned terrorism but that is not the core issue. It is all a case of how long it takes Islam to adjust to the mdoern world, and move on.
The threat of violence against the West is real enough but that is only a manifestation of Islamic unease and inability to cope with change. If they can externalise the situation, and accuse others of being the 'problem' that lifts the responsibility to achieve change from their shoulders. Every time we show a willingness to fight back in an argument we have little interest in, we fuel the fire, and supply oxygen to the extremists.