The Decision To Drop The Bomb

The Decision to Drop the Bomb

The decision made by the United States to develop and deploy the first nuclear bombs on the Japanese mainland in 1945 has been one of the most hotly debated issues of the latter part of the twentieth century. But to fully understand the situation, one needs to look back several years to the beginning of World War II.

During the 1930's some European countries began to reject democracy and embrace fascism and nationalism. This was a result of anger over the unfairness of the treaty of Versailles that was signed after the First World War. The Third Reich came to power in Germany on Feb 22, 1933 led by Adolph Hitler and his National Socialist German Workers Party. The government had a policy of racial, social, and cultural purity and pursued its aims through persecution and killing of those considered impure, targeted especially against Jews, Gypsies, Jehovah's Witnesses, and homosexuals. These unfavorable conditions in Germany and elsewhere in Europe enticed many scientists to immigrate to the United States. These included Jewish scientists Hans Betha, Edward Teller, and most notably Albert Einstein. These immigrant scientists found refuge teaching in American Universities.

In 1939 German scientists Otto Hahn and Fritz Strassmann discovered fission. It had been possible in theory but until that time no one had been able to sustain a fission reaction. This worried many scientists in America because this technology could be used to develop a weapon. This especially worried Leo Szilбrd, an immigrant scientist from Hungary. He drafted a confidential letter to Franklin D. Roosevelt explaining the possibility of nuclear weapons and warning that the Nazi's were working on such weapons. He enlisted the help of respected scientist Albert Einstein to sign the letter. Upon receiving the letter President Roosevelt handed the letter off to an aide, General Edwin "Pa" Watson with the instruction: "Pa, this requires action!" On October 11, 1939 President Roosevelt formed the Advisory Committee on Uranium. Around the same time scientists began to censor their research so it would not fall into German hands.

At this time the United States was still not at war but if faced a growing threat from Europe and Japan. After American Commodore Matthew Perry opened up Japan in 1853 with the Convention of Kanagawa, Japan was forced to industrialize to avoid being colonized by the western powers. The Japanese people believed that rapid industrialization was the only way to keep the Meiji Empire alive. Japan is the sixty-second largest country by area in the world and at that time was faced with the problem of increasing population and decreasing natural resources. Japan relied heavily on imported goods especially oil, metals, and rubber. Japan built a large navy to protect their shipping lanes and trade. They saw it necessary to invade Manchuria in 1931 to prevent rival nations preventing trade and cutting off their supply lines. Japan began to look to the rest of Asia mainly Indo-China. Japan thought that this could be a major resource of raw materials for their growing economy. In 1936 Japan signed an Anti-Comintern Pact with Germany and Italy on November 25, 1936. Japan invaded China on July 7, 1937 in what is now known as the Marco Polo Bridge Incident. The United States felt this was a threat and gave China economic and military aid.

In July of that year an oil embargo and other actions were put in place by the United States, the United Kingdom and the Netherlands. This dealt a crippling blow to the Japanese economy. Ninety percent of Japan's oil was controlled by the United States who demanded that Japan withdraw from China. Faced with no other options Japan began planning an attack on the United States. They chose Pearl Harbor on the Hawaiian Island of Oahu as their target because it was the home of the US Navy's Pacific Fleet which included 8 battleships, 8 cruisers, 23 destroyers and 3 aircraft carriers. Japan continued peace talks until thirty minutes before the actual attack. On the morning of Sunday December 7, 1941, the Japanese attacked Pearl Harbor with 441 planes and 5 midget submarines launched from an armada of 6 aircraft carriers and numerous other ships. The attack lasted only ninety minutes. When the smoke cleared 2403 American's were dead and another 1178 injured. The Japanese had sunk half of the fleet's battleships and damaged the other half, sunk three destroyers, damaged three cruisers and sunk two other ships. They had also destroyed 188 and damaged 155 of the 390 planes stationed at the nearby airbases.

The American public was utterly outraged. Japan's unprovoked attacked had killed many civilians and soldiers. They were also outraged that Japan had been continuing peace talks and had not declared war until after the attack. The next day the US declared war on Japan and 4 days later Germany declared war on the US. In the next several months Japan drove America out of the west pacific and the English and Dutch out of Asia. Japan conquered the Dutch East Indies, Singapore, Malaya, Burma, Indo-China, Wake Island and the Philippines.

After Pearl Harbor President Roosevelt approved production of a weapon and placed General Leslie R. Groves at the head of the project in 1942. Groves was not pleased with his assignment after just finishing the Pentagon that year. He did not believe that such a weapon could even be built. The bomb was designed at Los Alamos, New Mexico. The site was chosen because it was at an elevation of 7000 feet and accessible by only one road. Also because it was inland enough to evade possible enemy bombing raids. The army purchased 54,000 acres for $440,000 for the site and the nearby test range. Groves placed American Physicists J. Robert Openheimer at the head of the program. Openheimer was a very well known scientist and had taught at Berkley before the war. Openheimer draw big scientific names to the facility including Enrico Fermi, Richard Feynman, Robert R. Wilson, Hans Bethe, and Edward Teller.

Nuclear fuel was hard to find as the isotope of uranium that was required for fission, Uranium 235, occurred naturally at a rate of 1:139 to Uranium 238. It was hard to separate and the only two methods known were gaseous diffusion and magnetic separation which could be unreliable. The later discovered that plutonium could also be used to sustain a reaction. In 1942 the scientists at Los Alamos estimated that 200kg of U-235 was required to make a bomb. This would be 10 times more then required. As a result of the scarcity of nuclear fuel the president approved an additional 500 million in funding on December 28, 1942. Gen. Groves began building massive refinement and production facilities. By the programs end over 30 different sites would be built across the United