T20 Medium Tank T20 Medium Tank The Medium Tank T20 was part of a series of medium tanks designed by the United States during the Second World War, to be the successor to the Medium Tank M4 "Sherman", and culminated in the M26 Pershing. Almost immediately after the M4 Sherman was standardized, the US Ordnance Department started work on a successor. The Ordnance Department had already been working on heavily armored infantry tank design for the British, using M4 parts. The new project was started on the 25 May 1942, it was originally designated M4X. Starting with the T20, the Ordnance Department initially
US signals intelligence in the Cold War a decade of world change, with changes in Cold War alliances and emphasis, the first submarine attack since World War II in the context of a regional war involving extensive power projection, low- and medium-intensity operations, and continuing national policy development. Roughly from the late 1980s on, there was cooperation between the US and the PRC in collecting SIGINT of mutual interest, principally against Russia. It is believed that the Qitai and Korla sites, in Xinjiang (Sinkiang) are operated jointly by the Chinese and the US CIA Office of SIGINT Operations against Soviet missile tests and space launches, but their