Nuclear warfare

Nuclear warfare (sometimes atomic warfare or thermonuclear warfare) is a military conflict or political strategy in which nuclear weaponry is used to inflict damage on the enemy. In contrast to conventional warfare, nuclear warfare can produce destruction in a much shorter time-frame and can have a long lasting radiological warfare dimension. A major nuclear exchange would have long-term effects, primarily from the fallout released, and could also lead to a "nuclear winter" that could last for decades, centuries, or even millennia after the initial attack. 

Some activists had claimed in the 1980s that with this potential nuclear winter side-effect of a nuclear war almost every human on Earth could starve to death. However analysts, who dismiss the nuclear winter hypothesis, calculate that with nuclear weapon stockpiles at Cold War highs, in a surprise countervalue global nuclear war, billions of casualties would have resulted in the nuclear holocaust with billions of more rural people, nevertheless surviving.

So far, two nuclear weapons have been used in the course of warfare, both by the United States near the end of World War II. On August 6, 1945, a uranium gun-type device (code name "Little Boy") was detonated over the Japanese city of Hiroshima. Three days later, on August 9, a plutonium implosion-type device (code name "Fat Man") was detonated over the Japanese city of Nagasaki. These two bombings resulted in the deaths of approximately 120,000 people.

After World War II, nuclear weapons were also developed by the Soviet Union (1949), the United Kingdom (1952), France (1960), and the People's Republic of China (1964), which contributed to the state of conflict and extreme tension that became known as the Cold War.

In 1974, India, and in 1998, Pakistan, two countries that were openly hostile toward each other, developed nuclear weapons. Israel (1960s) and North Korea (2006) are also thought to have developed stocks of nuclear weapons, though it is not known how many. The Israeli government has never admitted to having nuclear weapons, although it is known to have constructed the reactor and reprocessing plant necessary for building nuclear weapons. 

South Africa also manufactured several complete nuclear weapons in the 1980s, but subsequently became the first country to voluntarily destroy their domestically made weapons stocks and abandon further production (1990s). Nuclear weapons have been detonated on over 2,000 occasions for testing purposes and demonstrations.

After the collapse of the Soviet Union in 1991 and the resultant end of the Cold War, the threat of a major nuclear war between the two nuclear superpowers was generally thought to have declined. Since then, concern over nuclear weapons has shifted to the prevention of localized nuclear conflicts resulting from nuclear proliferation, and the threat of nuclear terrorism.

The possibility of using nuclear weapons in war is usually divided into two subgroups, each with different effects and potentially fought with different types of nuclear armaments.

The first, a limited nuclear war (sometimes attack or exchange), refers to a small-scale use of nuclear weapons by two (or more) belligerents. A "limited nuclear war" could include targeting military facilities—either as an attempt to pre-emptively cripple the enemy's ability to attack as a defensive measure, or as a prelude to an invasion by conventional forces, as an offensive measure. This term could apply to any small-scale use of nuclear weapons that may involve military or civilian targets (or both).

The second, a full-scale nuclear war, could consist of large numbers of nuclear weapons used in an attack aimed at an entire country, including military, economic, and civilian targets. Such an attack would almost certainly destroy the entire economic, social, and military infrastructure of the target nation, and would probably have a devastating effect on Earth's biosphere.