620 Chapter 17 | Foreign PolicyNative Americans—adding much of the Midwest through the Louisiana Purchase—
and by annexing land after military conflicts, such as the large section of the Southwest
acquired from Mexico following the Mexican-American War. Later, America built the
Panama Canal, leasing land from Panama in the process, and sent troops into conflicts
in Nicaragua and other Central American countries. America also maintained
significant trading relationships with nations in Europe and elsewhere.
Still, America’s involvement in World War I (1914–1918) marked a sharp departure
in foreign policy, both in terms of the country’s participation in an international
alliance and the president’s willingness to continue alliance membership after the
conflict.^8 With the war almost over, President Woodrow Wilson offered a peace plan,
the Fourteen Points, which proposed reshaping the borders of European countries to
mitigate future conflict, creating measures to encourage free trade and democracy,
and establishing an international organization that would prevent wars.^9 American
diplomats participated in the negotiations that culminated in the Treaty of Versailles,
which officially ended the war.^10 The treaty created the League of Nations, an
organization similar to the modern UN, but the U.S. Senate rejected the treaty, which
meant that the United States never joined the League of Nations.^11The Rise of Internationalism World War II (1939–1945) marked a great transition
in American foreign policy. The United States became directly involved in the conflict
on December 8, 1941, declaring war on Japan the day after the country carried
out air attacks on Pearl Harbor in Hawaii and American bases in the Philippines.
Germany subsequently declared war on the United States on December 11. However,
even before the United States officially became involved, the U.S. military had
been supplying Great Britain and its allies with arms, ships, and other supplies in
return for payments and long-term leases on British military bases throughout the
world—actions that only narrowly escaped a congressional vote to reverse. During
the war, the Allied Powers—the United States, Great Britain, the Soviet Union, and
other countries—fought as a formal alliance, making joint plans and sharing military
hardware and intelligence.
After World War II, American politicians and scholars felt that the United States
should be a central actor in world affairs. This new policy was justified by realist
arguments, such as the need to deter future conflicts and the desire for economic
benefits from trading with other nations.^12 Liberals argued for the same policies on
the grounds that America had a moral obligation to preserve world peace.^13 However,
this shift toward internationalism only increased the amount of conflict in American
foreign policy, as actors disagreed on where the United States should get involved; what
its goals should be; whether intervention should involve military force, foreign aid,
diplomacy, or some other policy tool; and whether the country should act alone or in
concert with other nations.The Cold War Soon after World War II ended, the Cold War (1945–1991) began,
as the victorious Allies disagreed—with the United States and Great Britain on one
side and the Soviet Union on the other—over the reconstruction of Germany and the
reformation of Eastern European countries that Germany had occupied during the
war. In a 1946 speech, former British prime minister Winston Churchill referred to
an “iron curtain” that had split Eastern and Western Europe, leaving the East under
Soviet domination with few political freedoms.^14 American diplomat George F.
Kennan argued that America should use diplomatic, economic, and military means to
prevent the Soviet Union from expanding the set of countries that it controlled or was
allied with—a strategy that he deemed “containment.”^15 This idea served as a guiding
principle for American foreign policy over the next generation.^16Cold War
The period of tension and arms
competition between the United
States and the Soviet Union that
lasted from 1945 until 1991.containment
An important feature of American
Cold War policy in which the United
States used diplomatic, economic,
and military strategies in an effort
to prevent the Soviet Union from
expanding its influence.Full_18_APT_64431_ch17_614-654.indd 620 16/11/18 11:21 AM