For the Allies, in particular the French, this was based on a desire to avoid repeating the trench warfare of the First World War, which had occurred along the Franco-German border.
6,602 British: On land: 1,869 killed, wounded and missing At sea: c.
2,500 lost 1 aircraft carrier 2 cruisers 7 destroyers 1 submarine 112 aircraft French and Polish: 533 killed, wounded and missing 2 destroyers 2 submarines Norwegian: c.
In the following months aircraft from all the belligerents violated Norwegian neutrality.
Almost immediately after the outbreak of war, the British began pressuring the Norwegian government to provide the United Kingdom with the services of the Norwegian merchant navy, themselves being in dire need of shipping.
In April, the United Kingdom and France came to Norway's aid with an expeditionary force.