Racism not only implies race hatred but race war. The socio-political nightmare many people have is that the whole world could become a Bosnia or Rwanda where ethnic groups slaughter each other. A group is only a group if all its members share a common characteristic that non others have. In Bosnia you either are a Muslim, Croat or Serb. And being at the wrong place at the same time could mean death.
Terrorism is the new word replacing revolution.
Revolutions are counter-forces. They break mind-sets and substitute new ideas for them. They also kill and vilify people. Currently the revolutionary force mainly implied by the word terrorism is Islamic fundamentalism. These three ism words say a lot about popular understanding of current historical forces and counter-forces.