The Rebel Alliance in the Star Wars saga and the newly mentioned "Resistance" on the new "Star Wars: The Force Awakens" are suggested to be terrorists which are not much different to ISIS.
According to Forbes, the "Rebel Alliance" which is present in the film is a metaphor to the real-life terrorist group, ISIS. Because of this, a lot of critics described the "Star Wars" films as garbage. Writer Milo Yiannopolous said, "The Alliance is a ragtag band of fighters from many different cultures bonded together by a hatred of the Empire."
He added, "Fighting an assymetric war resulting in massive collateral damage and loss of civilian life. They take their lead from mystics hiding in caves and swamps, and want to return the galaxy to a primitive religion that hasn't changed for 600 years."
Luke Skywalker is now considered a concrete example on how ISIS works through his leadership. He does terrorist attacks affecting lives of the civilians just for the sake of his own beliefs. Just like this group, they do the same with the world as Milo described it.
Charles Camosy, another writer, argued with the LA Times and said that in order to be a terrorist, one must be able to use the deaths of the civilians just to achieve his purpose for whatever reason he may have in mind. So, that means, attacks meant for terrorism is simply not for killing. They need to have a goal to achieve using killing civilians.
He said, "If the death of an innocent person was either your goal or the means by which you accomplished your goal, then you're a terrorist. If the death of innocent people was not intended, then you're not [though your action may be morally wrong.]"
Based from the same source, by having a "Rebel Alliance" in all of the "Star Wars" films doesn't directly point out to any terrorist groups just like the ISIS. They are meant to "prevent the Empire from taking more lives and spreading their dark brand of galactic fascism any further."
In conclusion, their presence in the trilogy and the rest of the "Star Wars" films is just about maintaining balance and order.