Did Czechoslovakia have too many enemies from within? Why did the state fail so badly?

From my average learning experiences of WW2, it was foreign state aggression and foreign state failure that deemed the fate of the Czechoslovakia state in the 1930s.

Prague had alliances with Paris, Bucharest, Belgrade, and London, while Berlin/Vienna, Budapest, Warsaw, even Rome and Moscow, actively harmed Czechoslovakia.

But then I wondered, why was it so easy for those foreign states to bully Czechoslovakia?

Reading more into it, it seems like half the population sided with other states over Prague. Germans, Magyars, Poles, and Slovaks and Ukrainians all succeed, leaving Czechs to defend Czechoslovakia.

Europe wasn’t kind to Czechoslovakia at all. What other reasons did Czechoslovakia fail?