|Fig. 1: President John F. Kennedy's visit to the Nevada Nuclear Site. (Source: Wikimedia Commons)|
Deterrence, according to the Merriam-Webster Dictionary, is the inhibition of a criminal activity by fear, especially punishment and the maintenance of military power for the purpose of discouraging an attack. As nuclear weapons began to be the center of attention for major countries military development, it brought about many changes. It brought the ability for a country to completely annihilate its enemy and cause massive destruction to its enemies. Therefore, nations had to begin to factor this in about their own enemies; if a country knew its enemy had a large amount of nuclear weapons and nuclear capability, it would really need to evaluate a decision involving warfare against that country. Just think, if you knew one of your enemies could completely destroy half of your country at the flip of a switch, would you think long and hard before attacking or getting into some scuffle with this country?
After World War 2, nuclear weapons began to be the center of military research and with this growth came the idea of Deterrence theory. Thomas Schelling was one of the first to analyze this idea of deterrence theory and he wrote that military strategy was now much more dependent on deterrence, intimidation, and coercion. The amount of damage that a country could possibly do was now seen as a very influential factor for a country's decision-making and in order to deter another nation, the nation must expect violence and understand that it can be eluded. He says, "It can therefore be summarized that the use of the power to hurt as bargaining power is the foundation of deterrence theory, and is most successful when it is held in reserve."  (See Fig. 1.) This theory is centered on the idea that the possibility of unleashing nuclear weapons of mass destruction upon a country is enough to cause them to keep peace and deter a nation from doing anything aggressive.
Scott Sagan, a Stanford professor of political science, analyzed deterrence theory and the spread of nuclear weapons and developed a similar, yet different view from Schelling. He writes,
"An apparent contradiction lies at the center of our understandings about nuclear weapons and deterrence. On the one hand, it is widely believed that nuclear weapons were an important factor in maintaining the "long peace" between the United States and the Soviet Union during the Cold War. The two superpowers avoided war despite a deep geopolitical rivalry, repeated crises, and a prolonged arms race. On the other hand, it is also widely believed that the continuing spread of nuclear weapons will greatly increase the risks of nuclear war. New nuclear powers, with similar characteristics of rivalry, are considered unlikely to maintain stable deterrence." 
The idea of nuclear deterrence theory was one of the main reasons the U.S. and Soviet Union were able to maintain peace during such an intense time in history - both countries feared the damage the other could do with such a large amount of nuclear force. Deterrence theory is not as simple as it once was, but can still be applied to how we go about nuclear development today.
© Ben Baggett. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 T. C. Schelling, Arms and Influence (Yale University Press, 1967).
 S. D. Sagan, "The Perils of Proliferation: Organization Theory, Deterrence Theory, and the Spread of Nuclear Weapons," Int. Security 18, No. 4, 66 (1994).