Russia's entry into the war was like a bolt from the blue for Poland.
The Polish Army could not resist the German Army, let alone divert part of its forces to defend the Eastern Front battlefield while resisting the German assault.
Moreover, the Russian army had a tradition that Poland could never compare with, and that was the size of its forces.
Even in peacetime, the Russian army maintained a scale of millions, which was one of the reasons other countries were so wary of Russia.
After Russia entered the war, they would inevitably conduct partial mobilization. Don't be fooled by Russia's partial mobilization; the number of new recruits would definitely start in the millions.
This also meant that Russia could have an army of over two million at any time, nearly twice the current size of Poland's forces.
Facing Germany was already troublesome enough; adding Russia as an enemy caused some collapse within the Polish government and emboldened the previously hidden doves.
