Why did the U.S. become isolationist in the 1920s?

The US was isolationist in this period, in that it carried
on the tradition of not entering into binding security pacts. In other areas, the US was
far more involved in international politics than in previous
decades.

In Mesopotamia (modern day Iraq),
Britain and France vowed to keep a closed door on the country and refuse other countries
access to the increasing amount of oil being discovered. Standard Oil Company of New
York along with US government officials began a process of years of negotiations to
challenge this position, eventually leading to the American company taking control of
23.75% of the Turkish Petroleum Company in 1928. While the British did eventually work
behind closed doors to void this deal, American government participation to bring it
about in the first place goes against the idea of American isolationism in this
period.

Following the discovery of oil in Iraq,
American companies, again with US government officials, negotiated to be the sole power
to be granted permission to drill for oil in Iran. This deal also ended in failure,
because it relied on transporting the oil through the Soviet Union to the US. In
exchange for permission to transport oil through their country, the Soviet Union wanted
official recognition of their government which the Secretary of the Interior refused to
grant. Again, although this ended in failure, it is another instance that goes against
the belief of the US being isolationist.

In
Europe in the early 1920s, the issue of German reparations to the victorious powers was
a key issue and one that was important to the US. The Germans paying reparations allowed
Britain and France to repay their debts to the US incurred from the first world war.
However, Germany did not want to pay the reparations leading to a hyper inflationary
crisis in Germany, and the French to send it's army into the Ruhr valley. To resolve the
situation, Charles Dawes drafted and implemented a plan in 1924, known as the Dawes Plan
and approved by the US government. The Dawes Plan reduced the amount of reparations
Germany had to pay the Allies to 2.5Billion Marks over the next fifty years as well as
providing 2Billion US Dollars in loans to help boost the German economy. Five years
later in 1929, this was built upon with the Young Plan when it became apparent that the
Germans did not want to pay over such a long period of time, and again reduced
reparations payments by 20%. The willingness shown here for the US to get involved in
European affairs again counts against the belief the US was
isolationist.

One of the principle concerns of
the US government of this time was the cost involved in a naval arms race. The US had
drastically increased its naval capabilities during the First World War, moving from 4th
largest fleet to joint first with Britain. In 1922 the Government began talks at what
became known as the Washington conference, where global naval powers came together to
limit and reverse the naval arms race. The result of the conference was three treaties;
the Five Power Agreement between Britain, US, Japan, France and Italy where each pledged
to keep their navies at 5:5:3:1.67:1.67 respectively, the Nine Power Agreement where all
involved pledged to uphold the integrity of China, and a separate agreement between the
US, Britain, France and Japan to respect each others interests in the Pacific. In 1927 a
conference was called in Geneva to build upon the Five Power Agreement and stop a naval
arms race which had begun with smaller category ships. While France and Italy did not
attend, the US, Britain and Japan again pledged to keep smaller ships at the agreed
ratio of 5:5:3. In 1928, the US responded to France's repeated appeals for a security
pact. The US did not want to sign a pact with France whom had been rebuffed repeatedly.
To satisfy the French need for security, the US government called all governments of the
world to agree to what became known as the Kellogg - Briand Agreement. All but 5 world
governments attended, and pledged to make war illegal. All of these US led agreements
can be seen as a concerted effort by the US to be involved in world affairs, instead of
acting isolationist as previously
believed.

Latin America has always been a strong
sphere of influence for the US, and during the 1920s this was no different with large US
participation in the region. During this period the US; maintained garrisoned troops in
Haiti, Nicaragau and the Dominican Republic, controlled the politics of Cuba as well as
being involved in a decade long negotiation over oil rights in Mexico. By 1929 US
investments in Latin America had doubled from $1.26Billion to $3.52Billion, exports to
the region had tripled in value and now represented 20% of total exports by the US. US
involvement in the area wasn't unchallenged however, the US faced strong denunciations
at the Havana conference 1928 from the Latin countries, in particular Mexico and
Argentina, who resented US high handedness in the area. The US delegation ably defended
the government position, preventing an anti-US decision. In the end, the US abandoned
the Roosevelt Corrollary of the Monroe Doctrine, and instead sought the agreement of
other Western Hemisphere states when the US did decide to meddle. It can be seen from
the US interest in Latin America that these actions go against the belief that the US
was isolationist.

In the 1920s the US can only
be considered isolationist in that the US governments refused to be constricted by
binding security agreements with other powers, instead preferring agreements which bound
all powers as well as itself. Throughout the period the US consistently sought to
undermine British global supremacy, as well as defending it's own position gained after
the First World War. The US can be seen to have followed a policy of independent
internationalism.