Reddit reviews The History of Terrorism: From Antiquity to al Qæda

In short, no, at least going off of the definition of terrorism you wish to be used. This isn't, however, to say that terrorist groups do not effect change in the domestic or international scene. There are really two levels of objectives for terrorist groups: short-term and long-term. Short term objectives would be things like raising money by ransoming hostages or robbing banks, gaining media coverage, and recruiting members. This is really the meat and potatoes aspect of any terrorist group. Longer term goals are probably what you're looking for, and they are normally much more significant: regime change, the complete reversal of a government's policy, etc. Terrorist groups are much more successful with the former rather than the latter. Short-term victories are pretty common, with an example being the early 1980s bombings of the US embassy and Marine barracks in Lebanon, which eventually led to the US pulling out of the country. But I honestly can't think of one terrorist group that achieved it's goals strictly through terrorism. Exceptions to this rule would be when terrorism becomes part of a broader military strategy, often guerrilla warfare.

Furthermore, we have to recognize that, despite popular claims that terrorists are radical and uncompromising, their attitudes and objectives do change and their views have the potential to become moderated. The Muslim Brotherhood is a good example of this. The decision for moderation, or even the group's renunciation of terrorism, arises because, just like politicians, terrorist groups have their own constituencies. Of course, this discounts terrorist groups who see themselves as a revolutionary vanguard that will spring the masses to action, a la the RAF. In those cases, the terrorists group's views are often so far apart from any mainstream view that they never gain much in the way of any wider following, often because their nihilism alienates the ones they're trying to call to action. But going back to terrorist groups who actively work to form greater constituencies within a society, these groups often have to moderate their views out of necessity if they wish to have any type of political relevance. Sometimes, their constituents may accept that violence is a legitimate course of action, although there are certainly limits. For example, through the 1970s to the 1990s, the IRA and Sinn Fein heeded their constituency's demands by mainly attacking British security personnel rather than Protestant civilians. To have engaged in a wider program of civilian terror would have risked the group losing their legitimacy in the eyes of their constituency. (As a side-note this is not to diminish or marginalize IRA terrorist attacks against civilians, which still constituted roughly 20% of the group's terrorist actions).

Lastly, in some cases, a terrorist groups stated strategic objectives may not necessarily be the primary reason why they are committing acts of terrorism. The Weather Underground is a good example of this type of terrorist group. For the Weather Underground terrorism was an end in itself, an action that was a moral necessity against a corrupt and repressive government, no matter the tactic's efficacy. In these cases, the terrorist group's objectives are less important than the individual member's psychological catharsis through terrorism.

So, the objectives or goals of terrorist groups are multi-layered and constantly changing. Rarely, if ever, do their most radical objectives come anywhere near reaching fruition. When a terrorist group fails to moderate their views there are a few paths through which the group may follow, almost inevitably, to collapse. The group will be dismantled by the state (or a multi-state institution), which can occur through either violent or non-violent means (the Italian Red Brigades are a good example of this). The group dissolves through internal conflict, often arising over a debate as to whether terrorist violence should continue or if the group should moderate its views (the Weather Underground suits this path). The last is for the group simply to slip into irrelevance, fighting for a cause that no one cares about anymore. This final case tends to occur when terrorist groups refuse to adapt to a changing domestic/international scene, for example the RAF in post-unification Germany.

Edit: Wording.

Edit: I forgot to list some relevant sources for further reading if you'd wish to do so. For general histories of terrorism the best single volume is Gerard Chaliand and Arnaud Blin's The History of Terrorism: From Antiquity to al Qaeda. Bruce Hoffman's Inside Terrorism is also a must read. For an excellent look at the ideological motivations of the Weather Underground and RAF you can check out Jeremy Varon's Bringing the War Home: The Weather Underground, the Red Army Faction, and Revolutionary Violence in the Sixties and Seventies . Lastly, you may be interested to learn how exactly terrorist groups end. For that, two good books are Audrey Kurth Cronin's How Terrorism Ends: Understanding the Decline and Demise of Terrorist Campaigns or Seth Jones's and Martin Libicki's How Terrorist Groups End: Lessons for Countering al Qa'ida

I've done a bit of reading on terrorism and the most commonly accepted definitions of terrorism actually seem to lack terror. Terrorism is an act of small military value with the intent to cause a greater political effect, mostly through fear or inspiration ("calls to action"). These Islamists are a new breed and certainly not the standard-bearer for terrorists. I liked these books, 1 and [2] (https://www.amazon.com/gp/product/0520247094/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1)

I used excepts from this book when I taught an international relations survey course.