This is something I've started feeling quite strongly about lately, although I admit I'm partial to a bit of bias given my current enthusiasm for Cymraeg, but...
...why don't we teach Welsh as a second language in England? I say England because in Scotland and Northern Ireland they already have native languages that should be taught, but England does not.
I know some people will think, "Are you mad?!" but hear me out; my reasoning is sound:
1. Many children are more likely to visit Wales than Germany. German is taught in many British schools, yet British tourists to Germany number around 2 million per year compared to 10 million in Wales (2015 figure). This means more chance to practice a language learnt in school.
2. Welsh is the language of these islands. English people may not appreciate this, but our ancestors spoke something similar to Welsh. Before the Romans, Saxons and then Normans invaded, the native languages of these islands were the Brythonic languages, of these Welsh is the one currently in the healthiest state. Learning Welsh is a link to our past, even as Englishmen.
3. Learning any language has benefits beyond just that language. Learning one language helps a child understand other languages and their own language much better. There is nothing to be lost by learning Welsh and much to be gained.
4. Welsh is different. Welsh is not like French, German or Spanish; the languages children usually learn in school. The structure is different and it borrows little from Romance or Germanic languages. Learning Welsh gives children a different perspective on language learning yet remains relevant as it's spoken as a living language by 700,000 people and is an official language of the UK, unlike Cantonese, Mandarin or Satsuma ;)
5. Welsh is easy. Well, sort of. As I've covered previously, simple Welsh sentences in the past, present and future tenses can involve very little conjugation beyond the verb "bod" (to be). This makes progress fast and enthuses children to learn. Why spend two years mastering present tense conjugations in French when you can learn the same sentences in Welsh in a fraction of the time?
Not everyone will agree with me. I know the counter argument will be "but more people speak language X than speak Welsh!" or the usual "Welsh is a dead language! What's the point?!". But Welsh is growing. By teaching it as a second language it will grow more and these questions will answer themselves.