Nuclear weapons forever changed the nature of war, and the arms race between the United States and the Soviet Union dominated international relations during the Cold War. United States Develops Hydrogen Bomb. Led to New Round in the Arms Race.
President Harry Truman officially announced in 1953 the successful U.S. development of the hydrogen, or thermonuclear, bomb, which derives a large amount of its energy from the nuclear fusion of hydrogen isotopes.
The energy of an atomic bomb is the result of the fissioning of heavy, unstable atomic nuclei of uranium or plutonium. Unlike the fission bomb, the hydrogen bomb functions by the fusion, or joining together, of lighter elements into heavier elements.
Truman’s announcement led to a new round in the nuclear arms race with the Soviet Union, which developed its own hydrogen bomb 30 times larger than the atomic bomb dropped on Hiroshima and successfully tested it on August 12, 1953.
History of the Atomic Bomb
In 1934, Italian physicist Enrico Fermi discovered that by bombarding uranium atoms with neutrons he could split them into two other elements, with a small amount of the original matter transformed into energy.
Four years later, Hungarian physicist Leo Szilard found that as the split uranium atoms broke apart, they released neutrons, raising the possibility that they could set off a chain reaction in a millisecond, like the solar fire that American physicist J. Robert Oppenheimer was investigating.
Scientists realized that this had tremendous possibilities for the development of weapons. After World War II began, fear that Nazi Germany might develop a superweapon led the United States to launch the Manhattan Project, directed by Oppenheimer, in which uranium and plutonium bombs were created.
On August 6, 1945, an American B-29 dropped an atomic bomb on the Japanese city of Hiroshima, destroying 80 percent of the buildings in an instant. At least 80,000 people died. Three days later, another atomic bomb was dropped on Nagasaki, killing 100,000 more people and ending the war.
Several physicists working on the Manhattan Project envisioned a more powerful weapon employing fusion, not fission, an idea first raised by Fermi. When hydrogen is converted under intense pressure and at high temperatures into helium, the energy transition is potentially far greater. This process actually powers the sun.
The hydrogen bomb encountered intense opposition from many leading scientists, who believed that while atomic bombs could be justified as analogous to the conventional bombing raids that had destroyed such cities as Dresden and Tokyo during the war, the H-bomb would be a weapon of genocide.
Decision to Build the Hydrogen Bomb
The Soviet Union’s explosion of its first atomic bomb on August 29, 1949, changed the situation. American intelligence, then unaware of the Soviet infiltration of the Manhattan Project, had incorrectly predicted that it would take the USSR years to produce its own atomic bomb.
In September, President Truman shocked the nation by stating: “We have evidence that within recent weeks an atomic explosion occurred in the USSR.” The announcement caused panic among U.S. scientists and politicians, many of whom now advocated the development of a superbomb.
Most of the ensuing debate to develop the H-bomb was top secret. Physicist Edward Teller and others pressed for a high-priority program to build one and set out to persuade the U.S. government. The military Joint Chiefs of Staff supported development, stating, “The United States would be in an intolerable position if a possible enemy possessed the bomb and the United States did not.”
On January, 31, 1950, Truman publicly announced a crash program to develop the H-bomb. “I have directed the Atomic Energy Commission,” he said, “to continue its work on all forms of atomic weapons, including the so-called hydrogen or superbomb.” On March 10, he privately ordered the AEC to expand its facilities in preparation for production.
Hydrogen Bomb Tests
The first H-bomb was of the Teller-Ulam design, in which the radiation pressure generating the bomb sets off fusion in the secondary materials. The details remain classified, making it impossible to determine how much credit for the concept should be given to Polish émigré mathematician Stanislaw Ulam or Teller. Teller claimed it was his idea and is often called “the father of the H-bomb.”
On November 1, 1952, the United States exploded the first H-bomb. Code-named Ivy Mike, it was as large a leap in explosive power over the atomic bomb as the atomic bomb had been over conventional weapons.
It had a yield of 10.4 megatons, more than 547 times the explosion at Alamogordo, New Mexico, that ushered in the nuclear age on July 16, 1945, and released the equivalent of 19,000 tons of TNT. It vaporized Elugelab Island in the Enewetak Atoll of the Marshall Islands, creating an underwater crater 6,240 feet across and 164 feet deep.
However, Ivy Mike was a test device, not a weapon. It was not until March 1, 1954, that the United States tested an H-bomb capable of being used in actual warfare. The 15.4-megaton blast remains to this day the biggest nuclear explosion ever detonated by the U.S.
Tested at Bikini Atoll, the fireball measured three miles across in less than a second and was seen 250 miles away. Within a minute, the mushroom cloud was 47,000 feet high and seven miles across. One of the atolls was completely vaporized, disappearing into a huge mushroom cloud that spread at least 100 miles wide and dropped into the sea in the form of radioactive fallout.
Nuclear Test Ban Treaty
The fallout fell on the inhabitants of the islands to the east and on 23 Japanese fishermen who were severely affected by radiation sickness. The ensuing diplomatic and media outcry helped bring about the Nuclear Test Ban Treaty of 1963 that banned the atmospheric testing of nuclear weapons.
Twenty-three nuclear tests were made at Bikini between 1946 and 1958. The 1954 Bikini bomb remained the largest explosion until the Soviet Union’s 50-megaton test in 1961.
Half a century later, the design and construction of hydrogen bombs is beyond the capacity of all but the most technologically advanced nations. Only the five permanent members of the United Nations Security Council have them. Civilization as we know it would not survive even the briefest exchange of such weapons. As Oppenheimer, “the father of the atomic bomb,” once said: “I am become death, the destroyer of worlds.”