The primary argument for possessing nuclear weapons is deterrence, but what is deterrence?
Kayla Giampaolo, writing for the Carnegie Council for Ethics in International Affairs, describes deterrence this way:
Deterrence is a psychological phenomenon. It involves convincing an aggressor not to attack by threatening it with harmful retaliation. A psychological dimension is involved because the success of deterrence is not due solely to the retaliators capability, but to how persuasive the message of the threat is. In other words, in order for deterrence to work, the opponent must perceive the retaliatory threat as legitimate and serious.
Obviously, this approach works only if the opponent is a rational actor.
The object of deterrence has to believe you are willing to use nuclear weapons. In order to work, the potential adversary must be convinced that the negative consequences of an attack are not worth launching the attack in the first place.
Hiroshima and Nagasaki
Another powerful argument in favor of keeping nuclear weapons is the bombing of Hiroshima and Nagasaki. This argument doesn’t simply exist in theoretical ether. If this argument is sound, it provides strong empirical support for retaining nuclear weapons.
Surrender is essentially the ultimate shame in war according to Japanese thought, so it took a move of astronomical proportions to get the Japanese to surrender. This reasoning is fortified by the fact that Emperor Hirohito did not surrender after the March 1945 firebombing of Tokyo, even though 125,000 Japanese people were killed.
The US gave Emperor Hirohito the excuse he needed to surrender by dropping the bomb.Emperor Hirohito said:
The enemy has begun to employ a new and most cruel bomb, the power of which to do damage is, indeed, incalculable, taking the toll of many innocent lives. Should we continue to fight, it would not only result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization.
The need for nuclear weapons is clearly demonstrated by the bombing of Hiroshima and Nagasaki.
Keck says another benefit of the bombings was it showed the horrors of nuclear weapons. The physical and human toll will diminish any desire to get nuclear weapons.
Even though Keck doesn’t use this line of argument for possessing nuclear weapons, other scholars like Elbridge Colby use Hiroshima and Nagasaki to advance their argument. Colby is the Robert M. Gates Senior Fellow at the Center for a New American Security, he argues:
Moreover, countries now know about the prompt destructiveness that nuclear weapons can deliver. They have seen what happened to Hiroshima and Nagasaki. Japanese leaders in August 1945 knew none of these things. Perhaps equally importantly, Tokyo’s decision makers did not know this in December of 1941, when they decided to go to war. If they had faced a United States which they knew would annihilate most of the country’s urban landscape and military power in a relatively short timeframe, would they have gone to war? It seems unlikely.
… Nuclear weapons aren’t like other weapons. Used en masse, they are too destructive to be correlated with anything save vindication of a nation’s most vital interests. Thus they have changed the world, making it far more peaceful than the pulverized survivors of 1945 expected. But this means that stability and peace require not pooh-poohing the relevance or potency of nuclear weapons, but rather reminding our enemies and ourselves of their terrible power and of our willingness to harness that power to justified ends. (emphasis mine)
Colby argues that nuclear weapons are partially responsible for the relative peace we experience today.