If all of this is the fault of the US, How come the same thing happened to the other three?

If Mr Arar had returned to Canada it would have happened to all four.

You keep skipping over the fate of Mr. El Maati, Mr. Almalki and
Mr. Nureddin. You ignore that and focus only on Arar to defend Canada, and mount a mean spirited attack the US for doing the same thing that the Canadians did with the exception that Canada instructed the US to retain him.

Were you aware of Arar's Syrian citizenship and unfulfilled military obligation when you started this belligerent (as evidenced ny the title) attack? Were you aware of what happened in Tunisia?

If not you don't know all the facts and in large part acting in ignorance.

What happens when you give somebody shit? What do you get in return?

Do you need to be told what to do with your shit?