This post is an improved version after some interaction with a fellow advocating the moral basis for the development of nuclear weapons by any nation. It is a political tradition for governments to be concerned about weapons of hostile foreign governments. Perhaps it is because they are sometimes used in war. Unlike a chess game wherein it is usual to start the game with an equal number and assortment of pieces, in war the players do not try to make sure that their opponent (s) have an equal number of pieces.
Another problem is with weapons of mass destruction; they are just too large to be used very much on a planet like the Earth. Fluid dynamic political balances make power relationships regarding weapons stable and not used when they are constant. Proportional quality and quantity weapons changes by various nations tend to precipitate conflicts if/when conflicts occur.
That is why there has been attention given by politicians and negotiators to changes in weapons balances internationally regarding quality and quantity with demands that any signed treaties regarding weapons balances are honored (such as the A.B.M. treaty signed with the Soviet Union).
If there is an existing balance of power, in peaceful relations between nations, a change in the balance of power in weapons qualitatively and quantitatively between the nations favors opportunities for new conflict between nations. I can understand why nations that desire aggressive war would first want to change the balance of power.
In reply to those that feel there is no moral basis for denying nuclear weapons development to every nation.. “No moral basis’ is too broad, people tend to go for the all are and none are choices rather than some are and some aren’t, from the square of opposition. There are moral arguments pro or con for virtually any position and some are valid. It is a very high standard to prove that no valid moral arguments exist for a point.
Consider utilitarian arguments; act and rule based as well as consequentialist. Nuclear weapons are used largely on other nations rather than within one’s own to suppress dissent. Do nations have an innate moral right to have weapons designed to kill millions of citizens of other nations? The rule base version might decide their is, a priori, no reason to allow the lives of millions to be endangered, albeit with some mitigating circumstances, while the act based and consequentialist might decide to go ahead and let every nation arm with nuclear weapons to determine experimentally if it the best method of securing the greatest good for the greatest number.
Within the latter criteria; should the United States tolerate development of nuclear weapons by Germany and Japan on the principles of political, democratic equality? One could consider the criteria in the case of John F. Kennedy and the Cuban missile crisis that nearly brought World War III to fruition. Another moral argument would be quite plain; the development of nuclear weapons by Central Asian nations generally, that are independent, would greatly increase the chances for nuclear war and perhaps cascade billions of deaths. I believe some would conflate democratic and demographic national equality principles with the right to keep and bare nuclear arms, chemical and biological weapons of mass destruction.
The other point was about making an inference about aggressive war and nuclear weapons; I tend to regard anything less than a strict, necessary inference as fundamentally invalid. People commonly use or assume points that they can make a plausible inference for in rhetoric yet for those that require more than guesswork and speculation-such as in writing a computer algorithm, there is a great difference between necessary and unnecessary inferences. The latter might be regarded as psychological in some cases.