Against the advice of many of his senior military officers, in May 1940 Hitler ordered an attack on France and the Low Countries. They quickly conquered Luxembourg and the Netherlands and outmanoeuvred the Allies in Belgium, forcing the evacuation of many British and French troops at Dunkirk. France fell as well, surrendering to Germany on 22 June. The victory in France resulted in an upswing in Hitler's popularity and an upsurge in war fever in Germany.