... You realize that chart is bollocks though?

Nevermind that the source only lists 168 attacks, less than the graph claims for "Islamism" (There may have been cleanups in between, this still means the graph has bullshit data, as it used unsourced claims)

Nevermind that the source, lists "Islamism" as Islamic Extremism, making the chart seem like having an agenda.

Nevermind that the source article is an utter mess. Seriously, look at the talk page.

On top of all that, it's data is hilariously wrong.

The chart claims there have been 8 Irish Republicanism founded attacks. There have been over a dozen in the 1970s alone.

But even if the data were correct, (The end conclusion isn't going to change much when you fix the data, Islamic extremism has spawned a lot of terrorist attacks)

It still would be a bad chart. It doesn't control for other variables. While the Irish had to deal with a lot of bullshit from the British, they didn't get their countries bombed back several decades.

To clarify this with an example:

Let's say Russia manages to take over the US government through force, and anywhere from 30% to 60% of the population being on Russia's side. Unlikely, but just roll with it for now.

Clearly, this would lead to a lot of citizens revolting with force. (The right to bear arms is very important to this scenario)

Now, with the United States being both massive and having a lot of patriotism, and more importantly, guns. This would be an absolute bloodbath, that would dwarf even Islamic Extremism in terrorism.

Would, in such a scenario, the American patriots, and their ideology be evil? Of course not, but this is why you need to avoid data that doesn't attempt to correct for any other variables besides the few it highlights.