The Molotov-Ribbentrop pact between Nazi Germany and the Soviet Union realized Poland's worst fear. In September 1939, within one month of the signing of the treaty, Poland's two neighbors again attacked and divided the country. In the twenty years following World War I, Poland had been unable to modernize its armed forces or devise strategic and operational plans for defense against a Soviet or German attack. Hence in 1939 Poland was strategically isolated, unable to mobilize its troops, and technologically inferior. Although the Franco-Polish Alliance and Military Convention of 1921 required that a German attack on Poland trigger a French offensive against Germany in the West (terms that had been confirmed as recently as May 1939), the French did not come to Poland's aid when Adolf Hitler staged a border incident that brought Nazi forces storming onto Polish territory.

The large but underequipped Polish Army soon capitulated, and most of the force spent the war in prisoner-of-war camps. Underground resistance against German occupation began almost immediately, however, and resistance activity continued on Polish soil throughout the war. At its peak, the so-called Home Army (Armia Krajowa), directed by the London government-in-exile, included as many as 400,000 resistance fighters. Polish forces also fought under British and Soviet commands on the western and eastern fronts respectively. Poles fought with distinction with the Allies in Africa and Italy the number of Polish soldiers on the Western Front reached 200,000 by the end of the war.

A separate Polish army, recruited by order of Joseph V. Stalin from among Polish prisoners of war on Soviet soil in 1943, initially lacked officers and expertise. As a result, by the war's end about 40 percent of the officers in that force had come directly from the Red Army. In July 1944, on the strength of occupation by this Soviet-Polish army, a Soviet-backed provisional government was established at Lublin in eastern Poland. At the same time, the Eastern Front force, augmented by Soviet conscription in liberated territory, reformed as the Polish First Army under command of General Zygmunt Berling, who had been a Polish officer before the war. The Polish First Army later joined the Lublin-based communist resistance command to form the Polish Armed Forces (Wojska Polskie). In late 1944, two additional armies were added to this umbrella command all the Polish Eastern Front armies, which ultimately totaled about 400,000 troops, fought with distinction as the Soviet forces drove westward toward Germany in 1944-45 (see World War II , ch. 1).

The Polish armies on the eastern and western fronts remained under separate commands throughout the war, reflecting the political split that would substantively alter Poland's military doctrine after the war. The Soviet officer corps of the Eastern Front armies wielded a heavy political influence on their troops. Before the end of hostilities, an estimated 5,000 to 6,000 political officers were charged with indoctrinating military personnel in th26a the philosophy of the new communist political order that the Soviets planned for postwar Poland. By mid-1945, the Polish Army had adopted Red Army equipment, organization, regulations, and strategy, as well as the Soviet-type political apparatus that would become standard for all the armies of postwar Eastern Europe.

Data as of October 1992