From Neutrality to War: The United States and
Europe, 1921–1941
Overview
In the years after World War I Americans quickly reached the conclusion that their
country's participation in that war had been a disastrous mistake, one which should never
be repeated again. During the 1920s and 1930s, therefore, they pursued a number of
strategies aimed at preventing war.
At first the major players in this effort were American peace societies, many of which
were part of larger international movements. Their agenda called for large-scale
disarmament and an international treaty to abolish war. Their efforts bore fruit, as 1922
saw the signing of a major agreement among the great powers to reduce their numbers of
battleships. Six years later most of the world's nations signed the Kellogg-Briand Pact, in
which the signatories pledged never again to go to war with one another.
However, events in the early- to mid-1930s led many Americans to believe that such
agreements were insufficient. After all, they did not deter Japan from occupying
Manchuria in 1931, nor four years later did they stop the German government from
authorizing a huge new arms buildup, or Italy from invading Ethiopia. The U.S. Congress
responded by passing the Neutrality Acts, a series of laws banning arms sales and loans
to countries at war, in the hope that this would remove any potential reason that the
United States might have for entering a European conflict.
When in 1939 war did break out between Germany on the one hand, and Britain and
France on the other, President Franklin D. Roosevelt dutifully invoked the Neutrality
Acts. However, he believed that this was a fundamentally different war from World War
I. Germany, he believed (and most Americans agreed with him) was in this case a clear
aggressor. Roosevelt therefore sought to provide assistance for the Allies, while still
keeping the United States out of the war. He began by asking Congress to amend the
neutrality laws to allow arms sales to the Allies. Later on, after German forces overran
France, the president asked Congress for a massive program of direct military aid to
Great Britain—an initiative that Roosevelt dubbed "Lend-Lease." In both cases the
legislature agreed to FDR's proposals, but only after intense debate.
The question of how involved the United States should become in the European war
deeply divided the country. On the one hand, Roosevelt and the so-called
"internationalists" claimed that a program of aid to Great Britain and other countries
fighting against Germany would make actual U.S. participation in the war unnecessary.
On the other side stood those who were called "isolationists," who believed that the
president's policies were making it increasingly likely that the country would end up in
another disastrous foreign war. This debate was still raging when Japanese aircraft
attacked Pearl Harbor on December 7, 1941. At this point it was clear that, like it or not,
the United States would be a full participant in the Second World War.