Well im not that old, so i only got to experience 9 years in the 20th century, and, since you're seemingly not aware, we just got into the 15th year of the 21st century. That would mean I only experienced 11% of these two centuries; so yes basically and I bet you missed quite a bit too.
ok, from the turn of the 20th C: Anarchist terrorism, nationalism, WW1, Communism, Fascism, Naziism, WW2, Cold War, anti-Communism, left wing urban guerrilla movements in Europe, liberal interventionism, etc.
None of these were religious, all had people committing atrocities and horrendous acts in the name of doing 'good' or improving the world.
To paraphrase someone (forgotten who) 'Murder done for reasons of evil is a statistical rarity in human history. Murder committed for noble reasons is the norm'.
Relevant to this topic is the following quote:
"In 1957 a book of profound significance was published by a former wartime British Army intelligence officer named Norman Cohn... The Pursuit of the Millennium, Revolutionary messianism in medieval and Reformation Europe and its bearing on modern totalitarian movements. It was to prove one of the most influential and important historical and political books of the twentieth century.
Its argument, as Cohn summarized in the foreword to his second edition, was that in the past “traditional beliefs about a future golden age or messianic kingdom became, in certain situations of mass disorientation and anxiety, the ideologies of popular movements of a peculiarly anarchic kind.” He said that these movements in the Middle Ages possessed a hidden continuity and integral resemblance to modern totalitarianism in all of the latters’ excesses and terror.
Now we witness the arrival of ISIL... which is the counterpart in our time of such a movement. There is nothing new in it (unless this is its predilection for decapitations). Reading Norman Cohn will tell you all about it.
He will also tell you that it is a phenomenon that will pass. It is in no way integral to the Islamic religion, any more than Nazism was to German nationalism, or Stalinism to Marxism. For modern Muslims of the Eastern Mediterranean it is surely a terrifying phenomenon, because this movement has erupted from within their own society itself.
Europeans have seen Nazi terror and mass murder grow within their own societies. So have Russians. Colonial America had a large experience of it – as Cohn points out – in the witch-hunts of Puritan New England. One might venture to say (as some have) that in today’s American security state, with its all-encompassing surveillance, use of courts of exception and Star Chambers, perpetual imprisonment, and secret torture, one detects a shadow of it. Thanks to Professor Cohn, we can know it when we se it – and will understand that it too passes"
The Millennium Threat - Printer Friendly Page - Columns - William PFAFF
The Cohn book is excellent, and will help show that violent millenarianism is not unique to Islam, Christianity has a long tradition too.
A 2nd book is The Bullet's Song: Romantic violence and utopia, by William Pfaff. Another excellent book that shows that violent millenarianism is not unique to religion either and documents a variety of 20th century secular movements.
Would strongly recommend them to anyone who wishes to gain a more rounded understanding of current events beyond the superficial and naive anti-religious/anti-Islam viewpoint.