Denmark, Norway and Sweden were more fortunate than most European countries in that they were not directly involved in hostilities between 1914 and 1918. Both the Entente and the Central Powers were persuaded that they had more to gain from Scandinavian neutrality than from drawing the Scandinavian states into the war. Scandinavia proved marginal to the military and naval strategies of the belligerents to an extent unforeseen by pre-war planners. This was partly because the war lasted longer than most people had anticipated: much pre-war planning had been predicated on the assumption of a war of early engagements and rapid movement both on land and at sea – particularly in Scandinavian waters. It was also because attempts to break the deadlock on the western front by a flanking strategy were directed elsewhere: towards the eastern Mediterranean, not the Baltic. And because the war was prolonged, economic pressure became increasingly important to both sides. This heightened the significance of neutral Scandinavia as a transit route to Germany and Russia and as a source of supply to the Entente and the Central Powers.

In some respects their economic indispensability was advantageous to the Scandinavian states, or at least to the many individuals and firms who made large profits out of trading with the belligerents. However, most of the problems that confronted Scandinavian governments during the war resulted directly or indirectly from the attempts of the belligerents to conscript the Scandinavian economies into their respective war efforts. All three countries had to accept a drastic diminution of traditional neutral rights while establishing an unprecedented degree of government control and supervision over their domestic economies.