Answer:
In the short term: Threaten
In the long term: Maintain
Explanation:
The Cold War's arm race at the time threatened the world peace, as many were unsure that 1) another world war would occur, this time pitching Communism vs. Capitalism, 2) How this would affect other nations. As seen in Vietnam, Korea, & Afghanistan, many proxy wars were fought, while tensions heightened in events such as the Cuban Missile Crisis.
However, after the end of the Cold War, world peace was "easier" to maintain. America was left as the world's only superpower, which left the US to essentially take on the "watch dog"'s role. This allowed world peace to be maintained, as those who overstepped their boundaries faced consequences from the world's superpower.
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