<Li> Raids on the Atlantic Wall </Li> <Li> Battle of Atlantic </Li> <P> The Western Front was a military theatre of World War II encompassing Denmark, Norway, Luxembourg, Belgium, the Netherlands, the United Kingdom, France, Italy, and Germany . World War II military engagements in Southern Europe and elsewhere are generally considered under separate headings . The Western Front was marked by two phases of large - scale combat operations . The first phase saw the capitulation of the Netherlands, Belgium, and France during May and June 1940 after their defeat in the Low Countries and the northern half of France, and continued into an air war between Germany and Britain that climaxed with the Battle of Britain . The second phase consisted of large - scale ground combat (supported by a massive air war considered to be an additional front), which began in June 1944 with the Allied landings in Normandy and continued until the defeat of Germany in May 1945 . </P> <P> The Phoney War was an early phase of World War II marked by a few military operations in Continental Europe in the months following the German invasion of Poland and preceding the Battle of France . Although the great powers of Europe had declared war on one another, neither side had yet committed to launching a significant attack, and there was relatively little fighting on the ground . This was also the period in which the United Kingdom and France did not supply significant aid to Poland, despite their pledged alliance . </P>

What event began the second front in world war ii