I'd like to recommend you, one of my favourite TV series. It is based on the book of the former SAS operator Chris Ryan.
The story is about a fictional British Millitary Intelligence unit, the Section 20.
Tha main character is an ex-SAS operator, who made a mistake on a mission in Iraq, and the half of his team is killed. Ten years later, the daughter of a british politican got kidnapped in Iraq, and John Porter the main character discovers something similar with his previous mission. So he is back in the game at Section 20.
There are currently 3 seasons, the third will be finished in two weeks. The second and third seasons are made in american cooproduction, and are a bit different. One season has 10 episodes, and every story is 2 episodes.
(The last 2 episodes of Season 2 were made in Hungary, so you can see a bit from my country, and from our special police unit)
The show is realistic enough with a lot of actions. The characters are former SAS,SBS, or Delta operators, and even the bad guys were once spec ops.
I hope you'll check the show, and you will like it.