The background to, events of and consequences of the Battle of Mers- El-Kebir on 3 July 1940. In that battle, Royal Navy ships fired on the French Fleet in order to prevent it from falling into German hands. A French battleship was sunk and several other ships damaged. Nearly 1,300 French sailors were killed.
A good look at one of the stranger battles of World War 2. Strange in that England and France were, until only a few days before, allies. However, France's surrender to Germany had changed the relationship.
Shows well what lead to the battle, the options involved at the time of the battle, the detail of the battle itself and the consequences, including the effect on Churchill. Interviews with several relevant people, including English and French sailors who participated in the battle plus knowledgeable historians.
The documentary does take one step too many in its coverage, trying to turn the battle into something more controversial, editorializing and generally trying to slander Churchill. This is probably to appeal to the revisionist younger audience who somehow think that war is a game, to be played with neatly defined rules. When your country's very existence is at stake, it is not a game.
Other than that, very well done.