U.s. Resumes Bomb Research The United States answers Russia's violation of the atom test moratorium last fall by beginning a series of nuclear shots in the pacific. The U.S. Announces that the tests were resumed with great reluctance after the reds refused an iron-clad treaty. Bomb explosion. Aerial of Submarine, in water. Man in uniform looks through periscope. Interior of sub. Navy men present. Rocket fired from water. Tracking shot of rocket in flight. Aircraft in flight, turns direction. Bomb explosion, mushroom cloud.