During the winter of 1938–39, Goerdeler sent reports to the British that stated that Hitler was pressuring Italy into attacking France, planning to launch a surprise air offensive against Britain to achieve a "knock-out blow" by razing British cities to the ground sometime in the second half of February 1939, and considering an invasion of Switzerland and the Low Countries before an attack on France and Britain. Unknown to Goerdeler, he was transmitting false information provided by the Abwehr chief Admiral Wilhelm Canaris and General Hans Oster, who was hoping that the reports might lead to a change in British foreign policy. Canaris and Oster achieved their purpose as Goerdeler's misinformation resulted in first the "Dutch War Scare", which gripped the British government in late January 1939 and led to the public declarations by British Prime Minister Neville Chamberlain in February that any German attack upon France, Switzerland and the Low Countries would be automatically considered the "casus belli" for an Anglo-German war and would lead to the British "continental commitment" to defend France with a large ground force.