Remember how he sued the United States when he got back?
The Second Court of Appeals just dismissed his case on the following grounds:
It [the court] held that even if the government violated Arar's Constitutional rights as well as statutes banning participation in torture, he still has no right to sue for what was done to him. Why? Because "providing a damages remedy against senior officials who implement an extraordinary rendition policy would enmesh the courts ineluctably in an assessment of the validity of the rationale of that policy and its implementation in this particular case, matters that directly affect significant diplomatic and national security concerns " (p. 39).
In other words, the practice of shipping an individual -- any individual, visitor, immigrant, or citizen -- to another country to be tortured is de facto deemed legal because to even hold a trial on it could theoretically threaten national security.
A court in the United States has just officially sanctioned the use of torture.