FALL WEISS (September 1–October 5, 1939) but most were subsequently destroyed in the air by superior German fighters and Luftwaffe pilots, some with combat experience from Spain Within days, a few harried Polish Air Force survivors could little to stop Stukas and German fighters pounding retreating ground columns, or Do-17 and He-111 medium bombers terror bombing Warsaw The Poles expected help in the form of immediate Allied bombing of targets in Germany, to be followed by a French offensive along the Rhine agreed to start no later than September 15 Commitment to that date for a proposed French Army offensive—two weeks from commencement of any German attack on Poland—had been promised by the French High Command in May Timing was based on the French Army mobilization schedule However, there is no evidence that the Western powers ever seriously contemplated an offensive into Germany in 1939, or for that matter at any time during the Phoney War They decided instead that the only thing to was hunker down, continue their joint build-up and training of men for the long war of attrition they expected to fight against Germany, and wish the Poles “bon chance” in a sure-to-be-lost cause That was not mere cynicism: it was probably the only prudent strategy the Western powers could follow On September 17 the Soviet Union declared that the state of Poland had legally ceased to exist, and sent the Red Army to slash into eastern Poland to reclaim Tsarist provinces lost during the Polish–Soviet War in 1920 In fact, Soviet troops advanced to a secretly prearranged meeting line with the Wehrmacht established under an unpublished codicil to the Nazi–Soviet Pact The choice of September 17, with the Polish Army already effectively defeated, appears to have been the result of Soviet surprise at the speed of the German advance and attendant slow Red Army mobilization In addition, Stalin sought to separate politically and in propaganda terms his invasion from Hitler’s naked aggression Moscow’s attention was also drawn away from Poland to the Far East in early September, as the Red Army launched an offensive against the Japanese Guandong Army at Nomonhan A ceasefire with Japan was formally agreed on September 15 Assaulted on both sides, the Poles fought bravely but hopelessly to defend Warsaw for 10 days after the Soviet intervention The Wehrmacht pulled back to the partition line agreed with Moscow during the week of September 20–26 The Polish garrison in Warsaw surrendered on September 27 The rest of the Polish Army formally submitted on October The government had by then slipped into Rumania, thence into exile in Paris It would move to London the next year, as FALL GELB brought Blitzkrieg and death to France and the Low Countries Fresh Nazi–Soviet border adjustments were agreed in the immediate aftermath of the fighting There followed mass deportations of ethnic Poles and Jews along the new boundaries, accompanied by importation of ethnic Germans (Volksdeutsche) from the Baltic states to Poland In that brutal, forced movement of whole populations there was extensive cooperation between the Nazi Gestapo and the Soviet NKVD Berlin and Moscow then formally declared the Polish war over and Poland extinct as a nation-state They next called upon the Allies to recognize the new order they had jointly made in eastern Europe, to wit: destruction of Poland and the end of independence for the three Baltic States 372