The American definition of terrorism is “a premeditated and unlawful act in which groups or agents of some principal engage in actual or threatened use of force or violence against human property targets. These groups or agents engage in this behavior with the intent to intentionally intimidate governments or people to influence policies or behaviors with an underlying political objective” (Martin, 2014). There are several explanations for why terrorism occurs and why one would choose to take part in such acts of violence. According to the sociological approach, terrorism is group-based and is chosen by powerless groups as the only viable option. Structural theories of revolution emphasize that flaws in state structures allow for the possibility of rebellion. Proponents of this theory believe that a government overwhelmed by problems is susceptible to rebellion and run into trouble when their policies and procedures are distorted. Relative deprivation theory states that terrorism occurs when groups are dissatisfied or feel like their needs are being denied. According to Koseli, unequal distribution of healthcare, transportation and government benefits is associated with the number of terrorist incidents that occur in a particular area. Within psychological approaches there are individual-level explanations for the causes of terrorism. These explanations suggest that one acts violently because of a significant event that occurred in one's life. These individuals seek revenge or compensation from whoever they believe is the cause of their problems. There are also explanations at the group level. According to these explanations, terrorism occurs due to extreme driving forces within the group. They are likely to get a deal and… the medium of the document… refers to the terrorists' unequivocal certainty of the rightness of their cause” (Martin, 2014). They believe that the goals and purpose of their efforts are ethical and that their approach is acceptable. Moral conviction might occur when a group decides to have morally higher standing. This arises from intellectual convictions, religious beliefs or “ethno-national” standards. The radicals come to the conclusion that it is impossible to negotiate and that terrorism is the only alternative. Society may never truly know how terrorists think or what goes through their minds when they carry out these terrible acts of violence, and every terrorist group is different. Some theorists believe that the reasons are social while others believe that the reasons are more psychological or criminological. Terrorists may think that terrorism is their destiny or that it is their only option.