Explain the Manhattan project during the cold war and how two long-term causes created political or economic tensions between the US and the USSR. Long term cause:
explanation:

Organization (NATO) designed to oppose any Soviet invasion of Europe.  In 1949, the Soviet Union tested its first atomic bomb (closely resembling the plutonium device tested at Alamogordo, thanks to espionage).  That same year, Chinese communists defeated their nationalist opponents in the Chinese Civil War.  By the time communist North Korea attacked American-backed South Korea in June 1950, many in the United States and around the world believed that a third world war was imminent or had already begun.  

B-29s on a bombing runIn this atmosphere of national emergency, government officials believed that continued American superiority in nuclear weaponry was vital to preventing a third world war.  If a global war should begin, American military planners hoped that continued nuclear superiority would allow the United States to strike the Soviet Union with such force that damage to the United States would be minimized and that Western Europe could eventually be reclaimed from an invading Soviet army.  The generation of United States Air Force generals who had overseen the aerial destruction of the cities of Germany and Japan was determined to prevent similar destruction of American cities.  In 1950, following the beginning of the Korean War and a secret governmental study called NSC 68, the United States nearly tripled its defense budget.  

Ivy Mike, the world's first thermonuclear (hydrogen bomb) test, November 1, 1952.The defense buildup of 1950-1951 included an expansion of the nuclear weapons complex and an increase of the stockpile of fission weapons.  Truman also approved the design and production of the next generation of nuclear weapons, thermonuclear weapons (the "hydrogen bomb").  When the United States tested the first of these on November 1, 1952 (right), the result was an explosion that was equivalent to one produced by more than ten million tons of TNT.  This was approximately 700 times the power of the uranium (fission) bomb dropped on Hiroshima.  In August 1953, the Soviet Union tested its first "boosted fission weapon," which used thermonuclear burning to enhance its yield, and in November 1955 the Soviet Union tested its first true thermonuclear weapon.  There was now almost no limit on the size of an explosion either superpower could create.  In August 1957, the Soviet Union tested the world's first intercontinental ballistic missile (ICBM), a feat dramatized two months later by the launch of the "Sputnik" satellite.  The following year, the United States first began limited operation of its own ICBM.  One of these nuclear-tipped missiles from either side could arrive at its target in less than an hour, and no defense was possible once the missile was launched.  The only thing thought now to be preserving the "delicate balance of terror" was the promise that if one nation attacked, the other would surely retaliate.  The era of "mutual assured destruction," or "MAD," had dawned.  

Soviet R-7 ICBM (the type that launched Sputnik)No global third world war ever took place.  Mindful that a full-scale nuclear exchange would be a disaster for both sides, the superpowers fought each other through a variety of proxy wars and "shadow struggles" in Korea, Vietnam, Afghanistan, and dozens of other places.  The strategy of the United States and its like-minded allies was to use the nuclear threat to avert a direct Soviet attack on Western Europe and allow time for the eventual internal reform or even collapse of the Soviet Union and its satellite states.  Events eventually confirmed this strategy, but the Soviet Union in the interim proved willing to use overt military force to prevent the collapse of communist governments, most notably with its invasions of Hungary in 1956 and Czechoslovakia in 1968.  At the same time, the Soviet Union supported the spread of communism through insurrections and the overthrow of pro-western regimes in the third world.  The United States, in turn, responded with economic and military aid and, where necessary, armed force to prop up friendly governments and used its own secret intelligence services in attempts to overthrow unfriendly governments.

geography

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d. it gave farmers a way to organize for more political power