The Sri Lankan war wasn't Muslim - I said it was similar. More than ethnic, it was a linguistic battle - each side had Christian minorities within the majority linguistic group. The Tamils felt discriminated because Sinhala was the only official language, replacing English after Sri lankan independence (similar to the Quebec issue - would you classify that as an ethnic conflict too?).

As for immigration, let's take Italy as an example. It was an emigrants country till late 20th century. It's citizens emigrated to the USA, Canada, Argentina, Brazil, UK, etc. today they are a large recipient of immigrants. Ditto for the Irish, the Brits, the French, etc. London would never be the world's largest international financial center without those immigrants.

Let's take the USA. It is a hyperpower due to its immigration policies. if they had depended on the sons of the soil, they would have been a middling power today. They would certainly not have won two world wars and the Cold War.