The Specialist Schools and Academies Trust (SSAT) have recommended that pupils should learn subjects like history and geography in French to stem the decline of modern foreign languages. They said that students learned languages best in a bi-lingual environment, and schools that teach aspects of mainstream subjects in foreign languages had good results.
Actually there's one problem with language studies at school level in the UK: It's usually the history or geography teacher who ends up teaching the language, and that's often based on the qualification that they went on holiday there for two weeks once.