Question: What group was tasked with making nuclear weapons in April of 1939, and was sabotaged by the Allied Nations in World War II?
Context: The United States is known to have possessed three types of weapons of mass destruction: nuclear weapons, chemical weapons, and biological weapons.  The U.S. is the only country to have used nuclear weapons in combat, when it detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki during World War II.  It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project".  The United States pioneered the development of both the nuclear fission and hydrogen bombs (the latter involving nuclear fusion).  It was the world's first and only nuclear power for four years (1945–1949), until the Soviet Union managed to produce its own nuclear weapon.  The United States has the second largest number of deployed nuclear weapons in the world, after Russia. The World Federation of Democratic Youth (WFDY) is an international youth organization, recognized by the United Nations as an international youth non-governmental organization, and has historically characterized itself as anti-imperialist and left-wing.  WFDY was founded in London in 1945 as a broad international youth movement, organized in the context of the end of World War II with the aim of uniting youth from the Allied nations behind an anti-fascist platform that was broadly pro-peace, anti-nuclear war, expressing friendship between youth of the capitalist and socialist nations.  The WFDY Headquarters are in Budapest, Hungary.  The main event of WFDY is the World Festival of Youth and Students.  The last festival was successfully held in Quito, Ecuador, in December 2013.  It was one of the first organizations granted general consultative status with the United Nations Economic and Social Council. At the conclusion of World War II the Allied nations began the process of disarmament of Axis controlled regions.  Japan occupied Korea at this time and had been in control since 1910.  In 1945, the decision was made to have American Marines forces oversee Japanese surrender and disarmament south of the 38th parallel and the Soviet Union would facilitate the change of power to the north.  At the time there was no political motivation and seemed to be a logical and convenient plan of action.  The original agreement and intent was to create a unified and independent Korea out of the post Japanese occupation era.  Instead each side of the 38th parallel established its own government under the influence of the occupational country; the United States in South Korea and the Soviet Union in North Korea.  Both new Korean governments discredited the other and claimed to be the only legitimate political system.  Tensions between the North and South escalated and each side began to petition foreign powers for resources and support.  South Korea wanted weapons and supplies from Truman and the United States government while North Korea sought help from Stalin and the Soviet Union.  The United States was still war weary from the disruptive World War II campaign and refused South Korea's request for weapons and troops.  North Korea convinced the Soviet Union to supply them with the weapons and support they requested.  This decision coincided with the United States withdrawing the last remaining combat troops from South Korea.  North Korea saw its opportunity and attacked South Korean forces at the 38th parallel on June 25, 1950 and thus initiating the Korean War. The Norwegian heavy water sabotage (Bokmål: "Tungtvannsaksjonen" , Nynorsk: "Tungtvassaksjonen" ) was a series of operations undertaken by Norwegian saboteurs during World War II to prevent the German nuclear weapon project from acquiring heavy water (deuterium oxide), which could have been used by the Germans to produce nuclear weapons.  In 1934, at Vemork, Norway, Norsk Hydro built the first commercial plant capable of producing heavy water as a byproduct of fertilizer production.  It had a capacity of 12 tonnes per year.  During World War II, the Allies decided to remove the heavy water supply and destroy the heavy water plant in order to inhibit the German development of nuclear weapons.  Raids were aimed at the 60 MW Vemork power station at the Rjukan waterfall in Telemark, Norway. "Atomic spies" or "atom spies" were people in the United States, Great Britain, and Canada who are known to have illicitly given information about nuclear weapons production or design to the Soviet Union during World War II and the early Cold War.  Exactly what was given, and whether everyone on the list gave it are still matters of some scholarly dispute, and in some cases, what were originally seen as strong testimonies or confessions were admitted as fabricated in later years.  Their work constitutes the most publicly well-known and well-documented case of nuclear espionage in the history of nuclear weapons.  There was a movement among nuclear scientists to share the information with the world scientific community, but it was firmly quashed by the U.S. government. The German nuclear weapon project (German: "Uranprojekt" ; informally known as the "Uranverein"; English: Uranium Society or Uranium Club ) was a scientific effort led by Germany to develop and produce nuclear weapons during World War II.  The first effort started in April 1939, just months after the discovery of nuclear fission in December 1938, but ended only months later due to the German invasion of Poland, after many notable physicists were drafted into the "Wehrmacht". Sandia Base was, from 1946 to 1971, the principal nuclear weapons installation of the United States Department of Defense.  It was located on the southeastern edge of Albuquerque, New Mexico.  For twenty-five years, the top-secret Sandia Base and its subsidiary installation, Manzano Base, carried on the atomic weapons research, development, design, testing, and training commenced by the Manhattan Project during World War II.  Fabrication, assembly, and storage of nuclear weapons was also done at Sandia Base.  The base played a key role in the United States nuclear deterrence capability during the Cold War.  In 1971 it was merged into Kirtland Air Force Base. The nuclear weapons debate refers to the controversies surrounding the threat, use and stockpiling of nuclear weapons.  Even before the first nuclear weapons had been developed, scientists involved with the Manhattan Project were divided over the use of the weapon.  The only time nuclear weapons have been used in warfare was during the final stages of World War II when United States Army Air Forces B-29 Superfortress bombers dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in early August 1945.  The role of the bombings in Japan's surrender and the U.S.'s ethical justification for them have been the subject of scholarly and popular debate for decades. Nuclear weapons possess enormous destructive power from nuclear fission or combined fission and fusion reactions.  Starting with scientific breakthroughs made during the 1930s, the United States, the United Kingdom and Canada collaborated during World War II in what was called the Manhattan Project to counter the suspected Nazi German atomic bomb project.  In August 1945, two fission bombs were dropped on Japan, standing to date as the only use of nuclear weapons in combat.  The Soviet Union started development shortly thereafter with their own atomic bomb project, and not long after that both countries developed even more powerful fusion weapons known as "hydrogen bombs". The United States was the first country to manufacture nuclear weapons, with help from the United Kingdom, Canada and Australia, and is the only country to have used them in combat, with the separate bombings of Hiroshima and Nagasaki in World War II.  Before and during the Cold War, it conducted over a thousand nuclear tests and tested many long-range nuclear weapons delivery systems.
Answer: The German nuclear weapon project