After pro-US leader Fidel Castro gain the leadership of Cuba. he turn back to Soviet Union, then USSR offered nuclear missiles to Cuba. USA president Kennedy called a naval and air blockade of Cuba to force Kruschev remove the missiles. At first, Kruschev refused. but USSR's ship were blocked by America's ship to went Cuba island. Kruschev final agree and want USA promise not to invade Cuba any more. during Cuban Missile crisis, Prime minister Diefenbaker have conflict with present Kenndy about don't trust America.