Aug 1949Soviets test their firstnuclear weapon
Jun 1951US-Danish Treaty onGreenland effective
Aug 1953Canadian gov.moves Inuit familiesto populate High Arctic
May 1955Warsaw Pactformed
Aug 1958USS Nautilus makessubmarine crossingof North Pole
Jan 1959Alaska becomesUS state
Jan 1973Greenland joinsEuropean Communitieswith Denmark
17 Aug 1977Soviet icebreakerArktika reachesNorth Pole