Via TNTLog, the "Nanotech Dragon":
This is a scatterplot of current nanotech funding and scientists/engineers per capita in various countries. The US, Japan, and China are clearly in the lead today - but since "nanotech" is defined very widely, this doesn't necessarily reflect who will develop molecular manufacturing first. Here's a bit from Ed Regis' book Nano, back from when the word "nanotechnology" meant molecular manufacturing:
[Drexler's] reasoning here was that if nanotechnology was going to be developed anyway, whether he helped it along or not, then it was crucial that it be invented here in America, or at least by one of the free democracies wherever they were located, East or West. This was crucial because the first nation to develop nanotechnology would thereby become the world's dominant power, "the Leading Force".
That nation, whoever it was, could build weapons that no other country would have defenses against. Its citizens would become healthy, wealthy, and young overnight. It would be Them against everyone else.
Moreover, it was not out of bounds to imagine one of the more unspoiled worldy monarchies being the first to develop nanotechnology. Nanotechnology research, after all, was not "big science" in the usual sense. You didn't need anything like a Manhattan Project or an Apollo program or a Superconducting Supercollider effort to get the thing going. Conceivably, you could do it in a garage. You could do simulations of molecular machines on a personal computer; you could create billions of molecular structures in a test tube; you could custom-make DNA in a desktop synthesizer. All you needed for the great breakthrough was a laboratory, some extremely smart people and programming, and lots of luck at getting things right.
The above was written in 1995. "Healthy, wealthy and young", perhaps not overnight, but after only a few years is indeed imaginable. Tabletop or industrial nanofactories would allow their owners to fabricate any quantity of medical equipment with raw materials and the engineering design being the only costs. To truly defeat old age will require a thorough understanding of how the 7 mechanisms of senescence do damage and how to heal that damage without unhealthy side effects. Health will be boosted greatly by injecting ourselves with artificial antibodies and bacteriophages when they are developed, which should be before the closing of the second decade of this century. Wealth is probably the easiest item on the list to achieve, because what we consider wealth is largely based on material products, which can be manufactured in abundance when fabrication processes achieve high throughputs and are entirely automated.
Say you have a 10 kg nanofactory invented in an arbitrary country on January 1st, 2020. Let's say that the design is similar to the Phoenix nanofactory, in which case we'd work with the following assumptions:
The size, mass, energy requirement, and duplication time of this nanofactory design depend heavily on the properties of the fabricator. Sections 8.2, 8.3, and 8.4 quantify these relations. With the assumptions made in those sections, a tabletop nanofactory (1x1x1/2 meters) might weigh 10 kg or less, produce 4 kg of diamondoid (~10.5 cm cube) in 3 hours, and require as little as fifteen hours to produce a duplicate nanofactory.
Say that this first nanofactory is used to make a duplicate nanofactory, then both nanofactories are used to make duplicates, and so on, until you have 200 million units, ready for distribution to the majority of households in the nation. How long would this take? Under 28 duplication cycles, or approximately 18 days. In our model that would be January 19th, 2020. Assuming another week for distribution, this would put nanofactories into most homes in under a month since the technology was initially completed. To compare, the time it took for the Internet to be adopted by 50% of American households since its invention was about 15 years. The MP3 player and cell phone have arguably taken far less time to achieve 50% adoption, more like a few years. Nanofactories could achieve 50% adoption in weeks, possibly months or years if the price is kept artificially high, which is Michael Vassar's scenario in his Corporate Cornucopia paper. In any case, once a nation has 200 million nanofactories and the necessary raw materials, it could theoretically fabricate 2.3 billion metric tons of product per year, mostly durable goods, a productivity rate much greater than those seen in contemporary economies.
(If you read Greg's post in the comments, you'll see that early nanofactories would have high power and feedstock requirements, so the exponential explosion outlined above would be rather delayed. My model is partially based on the assumption that, unless a nanofactory has relatively low power requirements and can accept non-perfect feedstock, it isn't really going to be mass produced anyway.)
The question is, will the technology be available to everyone, or will it be guarded by a jealous few?
On the downside, restricting nanotechnology would have a horrible negative effect on many of the poorest people in the world, who have little access to housing, electricity, water, and other basic needs. Because the marginal cost of manufacturing an additional product using a nanofactory is so close to zero, people in poverty have the most to gain if nanotech is widely adopted, and the most to lose if it is restricted.
On the other hand, nanotech opens up a dangerous Pandora's box of problems that few people have even begun to understand. Nanoengineered weapons are in fact one of the greatest threats to humanity's future that has yet been imagined. Even if the threat of extinction were as low as 1/100, that's a 1/100 chance of the entire human future being destroyed, a future that potentially consists of trillions and trillions of beings experiencing worthwhile lives. It would be ethically prudent to hold back this technology until we can be better reassured that we can handle it with minimal risk. Unfortunately, in the real world you can't hold back a technology once international research gets started and investors are pouring money into it, which has already happened for nano. The upshot is that it might actually be beneficial for humanity if nanotechnology did end up being released to the public slowly, or in low-performance versions that make for a more fluid transition from manufacturing technologies of the past. But is that really practical once other companies and governments see the tremendous power of the technology and start developing their own versions?