1. Kennedy agreed to end the crises because they sent him a long rambling letter searching for a way out of the crises. The basic proposition was that if the U.S made a none invasion pledge then the soviets would remove their military presence in Cuba. From the U.S point of view, this was perfect.
2. Khrushchev agreed to end the crises because he wanted to avoid nuclear war and both sides acknowledged the risk, so both men agreed to end the crises to prevent war in any way possible.
3. On a scale i think both sides ended up winning because it could’ve ended up in a big devastating war between both sides of Kennedy would’ve refused the letter. Therefore i think both men won on protecting themselves from mass destruction on their land.
It would be the phrase "A. Look before you leap," that is most likely to be considered a cliché, since this is a very common and well-understood phrase in the English language, unlike the others.
