Almost every time terrorism has been tried it has worked for one simple reason. People get tired of it and give up.
Example 1: The American revolutionary war.
We broke away from England; King George did not like that so he sent in his army. We fought a war of terror, Small unit tactics, running away from larger forces to minimize losses, and only do hit and run battles until your can do better.
Result: The King got tired of losing troops and money so he gave up, and we "won" our independence.
Example 2: A state for Palestine.
After WWII Jews were not welcome anywhere in Europe and not all that wanted in America. The United Nations came up with a final solution of their own. Since Jews all over Europe were displaced already thanks to the final solution of the former Nazi party the ones that survived started heading back to Palestine mostly because they were unwanted everywhere else and it was the ancestral home for Jews since it was called Israel once they headed back. The problem was that people already lived there they were called Arabs and the land was occupied by the British. There was not place called Palestine yet. The terrorist (displaced Jews) first just started showing up but after a year or two there were too many people in the area and the Brits were not to be disobeyed. That is when the displaced Jews became terrorist, they fought the Brits and the local Arabs supplied the Jews with weapons and explosives.
This was done because the enemy of my enemy is my friend they really hated the British occupation so they tacitly supported the Jews who paid cash and killed the great Satan Briton. The Brits gave up but to save face and hopefully get rid of the Jews in Briton the UN allowed the Jews a homeland in payment for the Nazi final solution not turning out so good for the Jews. They were allowed to have a Palestinian state but could not call it Israel because that would offend the Arabs that surrounded the land the Brits owned and donated to the Jews.
Result: The day the vote was cast in the UN and a state of Palestine was created it died as the leaders of the new state dropped the name and called it Israel! Terror worked here because the enemy force gave up.
Example 3: Palestine Liberation Organization.
Not liking the fact that the Jews pulled a fast one the Arabs in the surrounding countries told the local Arabs not to become citizens of Israel and to fight the Jews. This has been raging for about 40 years in various forms. The reason it has lasted so long is the stupid Jews won’t give up! The problem is that they are running out of Palestinians because 90% have become Israeli citizens and are not fighting the fight and the rest are acting as not so smart bombs reducing their numbers.
Result: The new Palestinians are losing badly because terror wars only work for the short term, if the terrorist have not won in 5 years the statistics say they never will.
Example 4: Al Qaeda.
AQ is an offshoot of the Palestinian struggle only on a world wide scale. America has supplanted Great Britton as the Great Satan. The US is fighting them all over the world and AQ is losing all over the world. The only thing that keeps the terrorist movement alive is press to help recruits to act as not so smart bombs. The only way for them to win is for us to give up and stop fighting. The only way for us to win is to destroy (kill) all the terrorist that wish to die in order to kill us.
Result: too early to tell. The bad guys are running out of time to show some sign that they can do more than get killed. Five years is the longest a terror war lasts and wins.