Performing military maneuvers between countries can be challenging. Different countries operate their military in different ways and when you temporarily merge them not everything goes smoothly. In the month of September 1952 NATO members were performing naval exercises in the North Atlantic. Operation Mainbrace was the largest peacetime military exercise in the world, involving 200 ships, a thousand planes and over 80,000 troops participating from multiple countries. This was at the same time UFOs were seen over the White House in Washington DC two weekends in a row just a couple of short months earlier. UFO awareness was at a high state when the first UFO event happened within Operation Mainbrace. A Danish destroyer spotted a triangular UFO in the night sky moving at incredible speeds and you can find the rest of this cool story from the History channel HERE.