No, SASless it wasn't the PLO that started it. They didn't even exist until after 1948 when the returning Jews dispossed them.
Well before that there were organized political groups who chose terrorism as their primary instrument: The early IRA, the Bosnian Serbs who ignited WW1 and centuries ago the Indian Thugees - to name but a few.
I could guess that "terrorism" began when small bands of early Homo Sapiens first encountered small bands of Homo Erectus and probably butchered and ate them and raped their females - this is pure conjecture but traces of the interbreeding still exist in the modern human genome.
But in "modern" times it could be argued that religious terrorism started when most of the states in so called Christendom, on several occasions, amassed huge armies and set out to drive the (then peaceful) Muslims from their native lands by violence and pillage. They called them Crusades and they consisted of "Christian" armies inflicting gratuitous violence and butchery on innocent, peace loving, muslims. What a wonderful example we set them.
Rgds SOS
Last edited by SOSL; 20th Sep 2012 at 13:47.