Plan Zachód

Plan Zachód (Plan West) was a military plan of the Polish Army of the Second Polish Republic, for defence against invasion from Nazi Germany. It was designed in the late 1930s.

During the time Józef Piłsudski was the dictator of Poland, most of Polish planning concentrated on contingences in case of a possible attack from the East. It was only after Piłsudski's death in 1935 that the new Polish government and military reevaluated the situation and decided that the current Polish plan for a Polish-German war, dating from the mid-1920s (Plan "S"), was inadequate and needed to be revised. However up to 1938, the priority was war in the East, not the West, and a majority of Polish fortifications were being erected on the Polish-Soviet border.

The first version predicted that Germans would attack from Pomerania towards Warsaw, with supporting thrusts from Silesia and Prussia, aiming at establishing an early link through the Polish Corridor between German Pomerania and Prussia. After German annexation of parts of Czechoslovakia and changes of borders, Polish planners revised the plan with the expectation that a main thrust would originate from Silesia - through Piotrków and Łódź towards Warsaw and Kraków. The Polish planners correctly predicted the direction of most German thrusts, with one crucial exception: they assigned low priority to a possible deep, flanking, eastward push from Prussia and Slovakia, a push that was however assigned high priority in the German plan (Fall Weiss).

A controversy involved the decision whether Polish forces should defend the lengthy borders, or withdraw east and south and try a defense along a shorter line, backed with rivers. Although the second plan was more militarily sound, political considerations outweighed them, as Polish politicians were concerned that Germany could be satisfied with occupation of some disputed territories (like the Free City of Danzig, the Polish Corridor and Silesia), and push for an early end of the war after occupying those territories. The western regions were also the most densely populated and had major industrial centers, crucial for mobilization and any continued military production of equipment and supply for the Polish Army.

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