The Korean War began in 1950 when North Korea invaded South Korea, seeking reunification under communist rule. The US intervened under President Truman to contain communism and uphold the UN Security Council's call to defend South Korea. However, China also entered the war when US forces approached its border, leading to a bloody stalemate. The war heightened tensions in the Cold War and prompted a massive arms race between the US and USSR with proxy wars between their allies globally. An armistice in 1953 temporarily halted fighting on the Korean peninsula.

1. The Korean War
The Effects of Containment

2. US Policy as of 1950
 Communist victory in China leads the US to
reappraise its Cold War policy
 Review is carried out by the NSC, and results
compiled in NSC-68, which verified that Truman’s
policies were in line with Kennan’s Long Telegram,
and that the USSR was an expansionist, totalitarian
state
 Claimed that a strong Japan would be key to anti-
communist campaigns in Asia
 Asserted that US policy objectives could only be met
via increased military strength—including restoration
of US nuclear monopoly (H-bomb), and that a
powerful military should be a permanent characteristic
of the U.S.
 CONTAINMENT REPLACED WITH
CONFRONTATION.

3. The Korean War: Background
 North Korean army invades
South Korea in order to
reunite the country
 The USSR wanted the country
united as well, under the
northern leader Kim Il Sung;
the US wanted reunification
under the southern leader
Syngman Rhee; both
countries withdraw troops by
1949
 Defensive Perimeter speech:
Dean Acheson does not
mention Korea in a list of
countries the US will protect
from Soviet aggression

4. “The Korean War grew out of a double
misunderstanding: the communists, analyzing the
region in terms of American interests, did not find it
plausible that America would resist at the tip of a
peninsula when it had conceded most of the mainland
of Asia to the communists; while America, perceiving
the challenge in terms of principle, was less
concerned with Korea’s geopolitical significance—
which American leaders has publicly discounted—
than with the symbolism of permitting communist
aggression to go unopposed.”
Henry Kissinger, Diplomacy (New York: Simon &
Schuster, 1994), 475.

5. The action begins…
 Two days after North Korean troops move into South
Korea, Truman orders American naval and air units
into action; by June 30, American military forces are
on the ground in Korea, and on the island of Taiwan,
to supposedly protect it from communist takeover
 USSR had been boycotting the Security Council, and
was absent when Truman brought the Korea issue to
a vote.
Writes Kissinger, “America, said Truman, was going to
war to uphold the orders of the Security Council. It
was not, therefore, intervening in a faraway local
conflict but opposing an assault against the entire free
world.”

6. “In my generation, this was not the first time that
the strong had attacked the weak. I recalled some
earlier instances: Manchuria, Ethiopia, Austria. I
remembered how each time the democracies
failed to act, it had encouraged the aggressors to
keep going ahead. Communism was acting in
Korea just as Hitler, Mussolini and the Japanese
had acted…If this were allowed to go
unchallenged it would mean a third World War,
just as similar instances had brought on a Second
World War.”
Harry S. Truman, Years of Trial and Hope, 1946-
1953 (London: Hodder & Stoughton, 1956), 351.

7. “The American imperialists fondly hope that their
armed aggression against Taiwan will keep us
from liberating it. Around China in particular their
designs for blockades are taking shape in the
pattern of a stretched-out snake. Starting from
South Korea, it stretches to Japan, the Ryuku
Islands, Taiwan and the Philipines and then turns
up at Vietnam.”
Mao Tse-tung quoted in “The People’s Daily,”
quoted in Kissinger, Diplomacy, 479.

8. The US’s Objectives: 3 Options
Over the course of the war (1950-1953), the aims
of the United States (and hence U.S. Cold War
policy) shifted. Even at the outset, the U.S.’ goals
weren’t totally clear. It could…
1. Stop American forces at the 38th parallel and
restore the status quo ante (containment)
2. Authorize an advance beyond the 38th parallel
as a penalty for aggression (confrontation/roll-
back), or
3. Attempt to unify Korea all the way to the
Chinese border (confrontation/roll-back)
Truman and MacArthur decide to attempt to unify
the peninsula, which prompts China to enter the
war.

9. Stalemate
 Fearing Soviet involvement, and an all-out war
(instead of one limited to the peninsula), Truman
immediately shifts his policy to one of “halting
aggression,” rather than “being aggressive.”
“The Kremlin, Washington believed, would not accept
defeat; it would raise the ante after every setback for
its clients…The reality was quite different. Stalin had
gone along with the North Korean attack only after
Kim Il Sung had assured him that it would involve little
risk of war…The Korean War was not a Kremlin plot
to draw American into Asia so that it could then attack
Europe.”
Kissinger, Diplomacy,

10. The end.
 Eisenhower elected to the U.S. Presidency in
1953, threatens the use of the A-bomb
(brinksmanship)
 Stalin dies in 1953, thus allowing an armistice to
be signed
 Armistice line is drawn at the 38th parallel—after 3
years of war and with 10 million dead or injured,
little had changed.

11. Consequences?
 Launch of the arms race: huge increases in
military expenditures
 Development of “hot” wars between client states
in the Developing World—Cold War is now a
global, not just a European phenomenon
 US signs San Francisco peace treaty with Japan,
ending US occupation (1951-1952); Yoshida
Letter: Japan agrees to a trade boycott against
the USSR
 US signs mutual defense treaty with nationalist
Taiwan in 1954, and enters into defense treaties
with Australia an dNew Zealand

12. Features of post-1953 Cold War
 Globalised military + ideological confrontation
between opposing powers AND their client states
 Nuclear and conventional arms races
 Successive “limited” regional wars between
proxies/client states
 Spying and covert operations
 Intensified propaganda campaigns