Old habits die hard and nowhere is this more evident than in talk about terrorism. For many this is still an incorrigibly contested concept, and thus the word and its cognates still tend to be used exactly as a particular speaker or writer may choose. This is clearly a state of affairs that hobbles rational debate. If we are effectively to deal with the problem of terrorism (and especially international terrorism) we must accept a clear definition of the concept and stop hiding behind arbitrary and self-serving usages. This should not be a difficult project since the United Nations has already sent out a conceptual framework and begun filling in the detail. Of course, this is only the first stage in combination terrorism. The second is to amend the behaviour of states so that they no longer support such activities. For this to be effective it may be this strict measures will be required.