[Reed Melillo]

From what I understand, one of the primary justifications for the Manhattan Project was that the United States feared that Germany's nuclear weapon program was very advanced and close to, if not ready for, deployment of an atomic bomb. This rumor seemed to have been confirmed by German scientist Albert Einstein, who claimed that German scientists were well on their way to developing such type of weaponry.

Is it a valid argument that the United States used such a fear to justify the creation of the atomic bomb? It is common knowledge that Germany was in the process of developing a bomb, but how developed was their research?

[Smilin' Dave]

The fear of a German weapon does seem to have been a motivating factor. On the other hand the US were also motivated by their belief that the weapon would be effective, even decisive. Much the same also seems to have been true of UK nulear weapons research. Generally speaking a possible weapon that would work well was all the justification needed to fund such a project. Einstein regretted signing that letter, but also stated he thought it was necessary if the Nazis might be developing one.

It is common knowledge that Germany was in the process of developing a bomb, but how developed was their research?

German research seems to have hit a brick wall around 1942. Combination of political interference (eg. the obsession with 'German Physics'), brain drain (which was politically driven) and lack of funding.

http://en.wikipedia.org/wiki/German_nuc ... on_program

[William_H_Dougherty]

German research seems to have hit a brick wall around 1942. Combination of political interference (eg. the obsession with 'German Physics'), brain drain (which was politically driven) and lack of funding.

I was under the impression that Germany also lacked access to the essential rare materials required for the development of an Atomic Bomb.

The Allies had...well, access to Canada, which had and has ample supplies weapons-grade plutonium.

- WHD

[Smilin' Dave]

I was under the impression that Germany also lacked access to the essential rare materials required for the development of an Atomic Bomb.

Interestingly enough though the Soviets managed to confiscate enough fuel off the Germans to be worth their effort:

The single largest problem during the early Soviet project was the procurement of uranium ore, as it had no known domestic sources at the beginning of the project. The first in Europe Soviet nuclear reactor F-1 (nuclear chain reaction was initiated on December 25, 1946) was fueled using uranium confiscated from the remains of the German atomic bomb project. The Germans themselves got most of this uranium from invaded Belgium who mined it in its African colony Congo.

http://en.wikipedia.org/wiki/Soviet_ato ... iets_faced
Although point taken, it did take the Soviets longer (and by association, would have taken the Nazis longer) and they probably benefitted from the expanded mining of Uranium from domestic sources and elsewhere. Since the Nazis could pretty well forget about harnessing Soviet sources for uranium, that left them the heavy water method which didn't prove particularly viable.