Perhaps George in the magnitude of what nuclear weapons entail they are more easily self limited in their application.

Also they were used at least once on human civilizations and the whole world could examine the result and establish a measure for what later super weapons would wreak as damage.

The danger of nano is that until it is used there will be an almost irresistible temptation to underestimate the potential harm, or overestimate the potential threat. Can we afford one such conflict?

As not one but an entire arsenal of nano based weapons are developed we are diverting enormous resources into a non productive result and creating a dead-end for development due to the inevitable security clamps that would prevent spin-offs into more productive civilian applications.

We would also be developing such weapons with targets in mind and sooner or later the temptation to use them in conflict would create a whole new form of natural selection as humanity contributed to promoting one new *species* of nanobot to fight another new *species*. As one succumbed another would need to take the field in its place but at what environmental cost?

We simply could not know until the weapons were used and they could be designed as pseudoviruses to attack populations, agriculture, or even products like plastics and paper. They could be turned into chemical weapons that poison water tables making entire continental regions uninhabitable or end marine life. In fact they could be used in so many different ways that in a sense the danger of proliferation is vastly greater than with nuclear weapons.

Also initially they might require a significantly great industrial and academic effort to create them but after that they do not necessarily require that same level of investment to replicate the processes and streamline production but what of how to stockpile such weapons?

History shows that the odds are that if such an arms race occurs the weapons will be used at least once in conflict and is once already too much?

The longer such an arms race goes on without actually using the weapons the more devastating those weapons will be by the time of their almost inevitable first and maybe last use.

George, here's what we say about it on the CRN website:

An important question is whether nanotech weapons would be stabilizing or destabilizing. Nuclear weapons, for example, perhaps can be credited with preventing major wars since their invention. However, nanotech weapons are not very similar to nuclear weapons. Nuclear stability stems from at least four factors. The most obvious is the massive destructiveness of all-out nuclear war. All-out nanotech war is probably equivalent in the short term, but nuclear weapons also have a high long-term cost of use (fallout, contamination) that would be much lower with nanotech weapons. Nuclear weapons cause indiscriminate destruction; nanotech weapons could be targeted. Nuclear weapons require massive research effort and industrial development, which can be tracked far more easily than nanotech weapons development; nanotech weapons can be developed much more rapidly due to faster, cheaper prototyping. Finally, nuclear weapons cannot easily be delivered in advance of being used; the opposite is true of nanotech. Greater uncertainty of the capabilities of the adversary, less response time to an attack, and better targeted destruction of the enemy's resources during an attack all make nanotech arms races less stable. Also, unless nanotech is tightly controlled, the number of nanotech nations in the world could be much higher than the number of nuclear nations, increasing the chance of a regional conflict blowing up.

Admiral David E. Jeremiah, Vice-Chairman (ret.), U.S. Joint Chiefs of Staff, in an address at the 1995 Foresight Conference on Molecular Nanotechnology said: "Military applications of molecular manufacturing have even greater potential than nuclear weapons to radically change the balance of power."

An excellent essay by Tom McCarthy (unaffiliated with CRN) explores these points in more detail. He discusses the ways that MNT can destabilize international relations: MNT will reduce economic influence and interdependence, encourage targeting of people as opposed to factories and weapons, and reduce the ability of a nation to monitor its potential enemies. It may also, by enabling many nations to be globally destructive, eliminate the ability of powerful nations to "police" the international arena. By making small groups self-sufficient, it can encourage the breakup of existing nations.

www.crnano.org/dangers.htm#arms