The September Campaign was devised by General Franz Halder, the chief of the general staff, and directed by General Walther von Brauchitsch, the commander in chief of the upcoming campaign. It called for the start of hostilities before a declaration of war, and pursued a doctrine of mass encirclement and destruction of enemy forces. The infantry, far from completely mechanized but fitted with fast-moving artillery and logistic support, was to be supported by "Panzers" and small numbers of truck-mounted infantry (the "Schützen" regiments, forerunners of the "panzergrenadiers") to assist the rapid movement of troops and concentrate on localized parts of the enemy front, eventually isolating segments of the enemy, surrounding, and destroying them. The prewar "armoured idea", which an American journalist in 1939 dubbed "Blitzkrieg", which was advocated by some generals, including Heinz Guderian, would have had the armour punching holes in the enemy's front and ranging deep into rear areas, but the campaign in Poland would be fought along more traditional lines. That stemmed from conservatism on the part of the German High Command, which mainly restricted the role of armour and mechanized forces to supporting the conventional infantry divisions.