Once Germany had rapidly overrun Poland in September 1939, there was a sustained period of military inactivity for over six months that has been called the "Phoney War". On 3 April 1940, Chamberlain said in an address to the Conservative National Union that Hitler "had missed the bus". Only six days later, on 9 April, Germany launched an attack in overwhelming force on neutral and unsuspecting Norway after swiftly occupying Denmark. In response, Great Britain sent limited land and naval forces to assist the Norwegians.