Which additional realistic country breakups (more-or-less) along ethnic lines can you think of? In real life, we had Austria-Hungary, the German Empire (losing its Poles, Lithuanians, Danes, Czechs, French, and Walloons), the Ottoman Empire (sort of, since it lost its Arabs but kept a lot of its Kurds), the Russian Empire (Brest-Litovsk, though only a part of it actually permanently lasted before the whole Brest-Litovsk order was essentially restored as a result of the Soviet Union's collapse and breakup in 1991), Czechoslovakia, Yugoslavia (sort of, since the Bosniaks got way too large of a country), and the Soviet Union breaking up more-or-less along ethnic lines. Which additional countries could have realistically shared this fate, and ideally in fairly recent history--so, 1850 or later?
Iraq was, of course, a possible candidate for this, but if it survived ISIS, its unity is likely to permanently survive. Afghanistan I don't think is realistic unless there's some way to have it occur as a result of one of the World Wars since the Pashtuns in Afghanistan might simply be too strong and might thus successfully overpower any separatist movements there without any foreign intervention. Ethiopia is another possible candidate for this depending on how exactly its civil war will progress in the future. However, which additional realistic examples of this could you think of? Ideally scenarios that occur in 1850 or later, of course.
Iraq was, of course, a possible candidate for this, but if it survived ISIS, its unity is likely to permanently survive. Afghanistan I don't think is realistic unless there's some way to have it occur as a result of one of the World Wars since the Pashtuns in Afghanistan might simply be too strong and might thus successfully overpower any separatist movements there without any foreign intervention. Ethiopia is another possible candidate for this depending on how exactly its civil war will progress in the future. However, which additional realistic examples of this could you think of? Ideally scenarios that occur in 1850 or later, of course.