Many terrorist organizations are nationalists by another name.
Nationalist groups want freedom or independence from what they perceive as a outside power or force. Many terrorist organizations are formed to overthrow a government or gain access to nationalist state. ISIS for example wants an independent Islamic State which is free of Western influence. The Ku Klux Klan is a white nationalist group and also a domestic terrorist organization. Much of the terminology is perspective.
That was when the Declaration of Independence was sighned.
Answer: the right to bear arms