First I wasn't talking about the UK. Did you even read TFA? It's about what the US did, it just happens to be on Guardian, a UK newspaper.

Now, he who helped create ISIS, funded its operations, and enabled it to reign and kill people, in order to sell weapons and destabilize a region, is worse than ISIS.

What exactly is controversial about this?

That said, since you mentioned the UK: the UK had a billion people in Africa and Asia as slaves in its colonies just until 50 years ago. This, besides enslavement and resource-grabbing included countless executions, rapes, torture, aggression, war etc. ISIS has a lot of work to do to match up the numbers.

Don't make the mistake that the villain with the suit and the clean shave is much better than the crude foreign-looking fundamendalist villain.