Additional realistic cases of a country being more-or-less reduced to its ethnographic borders?

[WolfBear]

Which additional realistic cases could there have been of a country being more-or-less reduced to its ethnographic borders? In real life, there were:

-Germany, Austria, Hungary, and the Ottoman Empire all being more-or-less reduced to their ethnographic borders after the end of World War I
-Czechoslovakia being (briefly/temporarily) reduced to its ethnographic borders in late 1938 due to Nazi Germany's, Poland's, and Hungary's actions
-Russia being reduced to its ethnographic borders after the collapse of the Soviet Union. One could, of course, also say something similar about Serbia after Yugoslavia's collapse, though in Serbia's case, there were many more remaining Serbs outside of Serbia as a percentage of the total Serb population in Yugoslavia in comparison to Russia and Russians in the former Soviet Union.
-Ukraine being reduced to its ethnographic borders in 2014 as a result of both Crimea's and the Donbass's secession from Ukraine

There is, of course, another case of this which sort-of qualifies:

-India being reduced to its core Hindu borders as a result of the 1947 partition of India

And also, it's worth noting that had Kurdistan actually become an independent state at the time that ISIS would have risen (or beforehand), then Iraq would have indeed been temporarily reduced to its Shi'a Arab ethnographic borders due to it already temporarily losing most or all of its Sunni Arab-majority territories to the thankfully short-lived and ill-fated ISIS Caliphate.

Anyway, which additional realistic examples of this can you think of, either in real life or in alternate history? Any thoughts on this?

 

[WolfBear]

Some additional examples of this that I forgot to mention the first time around:

-Poland being reduced to its ethnographic borders after the end of World War II, as a direct result of this war. Of course, Poland also strongly benefitted from the mass expulsions of Germans in the West.
-France withdrawing from Algeria in 1962 and thus being more-or-less reduced to its ethnic French ethnographic borders.

Thailand's (Siam's) territorial losses before the start of World War I are a bit of a border case. Thailand was made overwhelmingly ethnically homogeneous (Thai) as a result of this, but it also lost some territories that it arguably shouldn't have lost, such as Laos.

 

[WolfBear]

-Germany, Austria, Hungary, and the Ottoman Empire all being more-or-less reduced to their ethnographic borders after the end of World War I

This World War I-era map does a good job portraying the World War I-era situation in regards to this:

 

[WolfBear]

I suppose that Sudan can sort-of qualify for this due to it losing most of its non-Arab territories in 2011 when South Sudan seceded from it:

It would, of course, help if Sudan also eventually ended up losing Darfur.

 

[WolfBear]

One could, of course, also say something similar about Serbia after Yugoslavia's collapse, though in Serbia's case, there were many more remaining Serbs outside of Serbia as a percentage of the total Serb population in Yugoslavia in comparison to Russia and Russians in the former Soviet Union.

One could also talk about Serbia being reduced to its ethnographic borders during World War II after the Nazis invaded Yugoslavia in 1941:

Compare this with the core Serb ethnographic territories in Yugoslavia in 1981: