The Nordic countries include Sweden, Norway, Finland, Denmark, and Iceland. These five countries are all sovereigns of the Nordic Council. There were six main battlefields in the first half of World War II, among which the opening of the Western Front battlefield in Europe represented the full outbreak of World War II. In 1939, Germany attacked Poland with a blitzkrieg. Although the Polish people and the army resisted heroically, after more than 20 days of tenacious fighting, Warsaw fell and Poland was occupied by Germany and the Soviet Union. After that, Germany moved all the way northwest and launched an attack on Northern Europe.

The first to bear the brunt of the Nordic battlefield is Norway. Norway’s unique fjord terrain is a natural port for the navy, facing the United Kingdom by the sea, and Norway is also the entrance to the Strait of Jutland. These geographical conditions are destined to Norway will be a strategic military location that the Axis Powers and the Allies compete for. When Germany's iron ore supply was in crisis, Hitler's first thought was to attack Norway. Norway's military strength is far inferior to that of Germany, but the German army encountered resolute resistance from the local armed forces after entering Norway. After ordering the air force to bomb the hiding place of the Norwegian king at that time, the king miraculously survived and summoned the remaining troops and the British and French and Polish reinforcements attacked Germany together. Although Germany won the Battle of Norway, the losses in this battle were much higher than Germany had expected.

After occupying Norway, the German army directed artillery fire at Denmark. After receiving the ultimatum, the Danish king decided to accept "German protection" four hours later. Due to Denmark's non-resistance policy, Germany almost There was no control over Denmark. Compared to Poland, which was occupied at the same time, Denmark was almost unscathed.

Except for Norway and Denmark, Sweden was spared from the war in World War II because of its strong military strength and its neutrality policy favoring the Axis powers. Iceland was because it is surrounded by sea and is close to the remoteness of North America. position, and was not dragged into the battlefield by the German army. After the Soviet Union partitioned Poland in 1939, it invaded Finland. After the Soviet-Finnish Battle, Finland announced that it would join the Axis powers in the Barbarossa Plan.