Polish forces were concentrated in the east awaiting the war with the Bolsheviks,
No they were not: they were actually fighting against the Ukrainians. Those same Ukrainians who then became allies of Poland and were sold to the USSR when Poland no longer needed them.
the Czechs took this opportunity-in true cowardly fashion to attack Poland,
Actually they requested that Poland stopped its preparations to break the interim agreement signed in 1918. When Poland refused to do that, the Czechoslovaks acted.
going to great lengths such as dressing their soldiers in foreign uniforms in preparation for the attack.
That's a lovely lie. But you'd better sanitise wikipedia: it currently says "On 23 January 1919 at 11:00 in Cieszyn Silesia Polish commander Franciszek Latinik and Czechoslovak officer Josef Šnejdárek met with a group of officers, consisting of English, French, Italian and U.S. representatives (at the request of the Czechoslovak party). The Polish side was given an ultimatum, that they evacuate the area to the Biała River in less than two hours. After the expiry of this period the Czechoslovak army started its operations at 13:00 following its operational guidelines to seize Bohumín and Karviná."
Their action was inspired by the same sort of bravery which resulted in them being taken over without a shot being fired in the Second War.
And who was first to invade Czech territory? Poland. Got in there even before the Nazis. Good work guys.