This is definitely one of the best spy thriller series I have seen. The story is well-written, the producers and writers have clearly done a lot of research into making this fictional spy series as realistic as possible. Every mission they portrayed are fraught with unexpected events that will keep you to the edge of the seat. The characters are well-written and will keep you invested that you would want them to survive or escape any potential dangerous situation.
Having watched this 10 years when it first came out, I can still remember certain scenes; most notably one was when the severely dehydrated and exhausted protagonist was being chased by a suicide bomber in the desert.
Great series and I would highly recommend. Definitely warrants multiple watches.