Hitler's orders on 1st September were accompanied by detailed orders signed by Keitel, for the imminent defence of the West Wall; but the advance of the western Allies, already in Belgium and on the Meuse, had now deprived the Germans of the initiative, as Hitler's next Order, of 3rd September (No. 64), shows. The very next day, September 4th, British forces entered Antwerp, thus cutting off the Channel ports and the Pas de Calais, with the launching sites for the flying bombs. Hitler at once gave orders for the fortresses of Boulogne and Dunkirk to be reinforced and held at all costs, and for the Albert Canal from Antwerp to Maastricht to be defended. Three days later, on 7th September, Hitler reversed his recent decision to entrust the defence of the western frontier of the Reich to the Chief Of The Replacement Army, and restored full power to Field Marshal von Rundstedt, the Commander In Chief In The West (Nos. 64a and 64b).