I think that one enters a very challenging domain with such a question. It is clearly important that one delineates elements in understanding how volatile the topic is. On one hand, I think that a basic element that is present in many outgrowths of terrorism is a lack of economic and social opportunity. For many who embrace terrorism, it arises out of a lack of social acceptance and economic integration. It is this marginalization that makes people, especially young people, prime recruiting targets for terrorist activity. When terrorist organizations seek to broaden their reach and recruiting reach, the targets are young people who have little to which they can hold, little to which they are included. It is for this reason that the terrorist finds that the young and the marginalized end up becoming prime territory. This helps to explain why terrorism in certain contexts arise in which terrorism becomes a way in which people are attracted to and could embrace it. I think it is important, though, to make clear that embracing terrorism does go against the fundamental tenets of democratic self- rule and participatory government, so in this light, I am not sure that terrorism could ever be justified, although it might be able to be explained.
Great comment, thanks akannan