I`ll add something. When Germans walked into Czechoslovakia in March 1938, except Romania (right?) bitting off a part of that country, also polish troops (!!!!) invaded and took city of Cieszyn and its surroundings.
I bet most of you didn`t realize that on the eve of war Poland
actually attacked another country
Why did it happen? Czechoslovakia invaded the same city during Russo-polish war when (and that`s another conflict) all polish forces were busy on the eastern front. There`s an interesting history behind that, some ill equipped polish volounteers defending that city from Czech forces for few days before they had to retreat. So polish 'invasion' (too big word) from the end of 1938 was a form of revenge for the previous czech attack.
It was rather a fulitle victory, as it was similiar to kicking someone already laying on the ground. Poland would do better by supporting Masaryks government against Hitler. Especially that world media didn`t like the polish attack on Cieszyn.
On a sidenote. From 1919 to 1921 there were 3 polish uprisings in Silesia. The outcome was that whole northern part of it, with important mines and factories went to Poland.