Rendition is about an Egyptian American who is sent to a North African country as he is suspected of having some connection with a terrorist. There of course he is tortured. This process of handing out suspects to other countries to be tortured is known as extraordinary rendition.
The impressive parts of the movie are what happens in North Africa. The torture scenes are not easy to watch but affect you a lot. Also, the subplot about the daughter of the local law enforcement guy overseeing the torture is also very interesting.
On the other hand, the acting of Meryl Streep, who is a great actress, and Reese Witherspoon did not impress me much.
Overall, I rate the movie 8/10.
And finally a question: Considering that the United States has (indirectly) tortured innocent people via extraordinary rendition (for example, Maher Arar), do you worry something like this could happen to you or your loved ones? Also, please note that extraordinary rendition did not start with the war on terror. Instead, it dates from the war on drugs as Jonathan Edelstein shows in a great blog post.