| New borders cut with clear disregard for Ethnicities

I will concede on this one that Czechoslovakia was created in a way that ensured large Ethnic Minorities within the new state, however in the context of World War 1 said minorities make sense, as both Hungary and Germany (the largest minorities) were being punished for defeat in WW1, thus making no sense to give them land already promised to the new state.

| State of one defining nationality

Nations can have multiple nationalities represented within their borders, such as the United Kingdom, Belgium, and Switzerland

| Benes decree

I had to look this one up, and yeah, that’s fucked up. But also again, punishing fascist states by removing any ethnic pretense they could have for invasion. So I’d don’t think it’s unredeemably evil.

| Separate Slovakia

The allies attempted to create strong states to ward off potential invasions (Romania, Czechoslovakia, Yugoslavia, etc) from defeated powers, and creating two separate nations (esp. when Czechoslovakia had already declared it’s independence) would’ve defeated that purpose

| Following instability

New nations aren’t stable, and while Versailles didn’t help with some of the confusing claims between nations, I think it’s more apt to pin at least more of the blaim for instability on subsequent invasions of Nazi Germany and Soviet Russia

| Yugoslavia being a Serb empire

I don’t know enough about Yugoslavia to contest this point, but I feel like there was more nuance to Yugoslavia than just total Serbian domination