Massive transfer of my million-man army to repel Poland's treacherous attack against me. Military recruitment offices in major cities are activated, and a total mobilization begins. The counter-attack against the Polish traitors is launched. Special aircraft sweep over territories occupied by the Polish army, spraying our special gas that causes horrific lung scorching and rapidly degrades most gas masks. Since the Poles lost their organization due to their 'blitzkrieg', rapidly arriving Czechoslovak units managed to push them back slightly. Massive partisan movements are starting within the occupied territories of Czechoslovakia. All nuclear power plants previously built in Czechoslovakia will be detonated one by one at the exact moment the wind blows towards Poland, aiming to poison and render most Polish lands uninhabitable via a radioactive cloud. A militia mobilization begins, drafting children, the elderly, and absolutely all youth and military-eligible citizens. The entire economy urgently shifts to a war footing. Aviation and drones (reminder: they run on AI and are unhackable) take to the skies and begin terrorizing the Polish army. All borders are urgently closed. A massive propaganda campaign is launched, declaring Poland a nation of traitors who brutally stabbed us in the back after we protected them from German aggression. A proposal is sent to the Baltic Union and Sweden to form an Anti-Polish Coalition. The Central European Federation is called into the war as an ally. Furthermore, I request assistance from the Caribbean Union and Eskaijiani, as they are members of the (PU) Global Defence Organisation.
By the way, you never said the size of your army, smart guy.