"Berlin historian Rainer Karlsch claims that the Nazis conducted three nuclear weapons tests in 1944 and 1945. But he has no proof to back up his theories". Says it all, really.....
That aside, the "Spiegel" article is actually a pretty good debunk of Rainer Karlsch' work. From later in the article:
"The only problem with all the hype is that the historian has no real proof to back up his spectacular theories.
His witnesses either lack credibility or have no first-hand knowledge of the events described in the book. What Karlsch insists are key documents can, in truth, be interpreted in various ways, some of which contradict his theory. Finally, the soil sample readings taken thus far at the detonation sites provide "no indication of the explosion of an atomic bomb," says Gerald Kirchner of Germany's Federal Office for Radiation Protection".
There's a review about Rainer Karlschs book from the german newspaper FAZ,
which I think, sums up the arguments quite good: Nothing really new, with the
exception maybe of the role played by Kurt Diebner, a german scientist, who perhaps
had driven his research into a nuclear bomb further, than still yet acknowledged.
But nothing new about nuclear tests, or other hard evidence. Karlsch says "yes", where
others say "no". What's the chance of two or even three nuclear explosions, to have
remained secret until today ?
Funny, the last part of the review points out, that the book, unintentionally by the author,
underlines , that Germany during those times was unable to achieve a scientific and tech-
nological result, for which the USA had employed around 160.000 scientists, engineers and
technicians. So the title of the review, "Hitlers Bombenbastler" (Hitlers Bomb Tinkerers) seems
to be a good match to Rainer Karlschs somewhat blatant title.
We probably will still see a lot of those books in the future, because there's still a large market
for them. But that doesn't necessarily means, that there are new arguments!