Yes the Battle of Britain staled Germany's invasion plan. But ... had it not been for lend-lease and then the USA entering the war, you'd all be speaking German anyway, and so might all of Europe and a big chunk of what was the USSR.
The German High Command and Hitler never showed any interest in atomic weapons. Here's the intoduction to the wiki article on the subject:
The
German nuclear weapon project (
German:
Uranprojekt; informally known as the
Uranverein; English: Uranium Society
or Uranium Club), was a clandestine scientific effort led by
Germany to develop and produce
nuclear weapons during
World War II. This program started in April 1939, just months after the discovery of
nuclear fission in January 1939, but ended only months later due to the
German invasion of
Poland, after many notable physicists were drafted into the
Wehrmacht.
A second effort began under the administrative purview of the
Wehrmacht's Heereswaffenamt on 1 September 1939, the day of the Invasion of Poland. The program eventually expanded into three main efforts: the
Uranmaschine (
nuclear reactor), uranium and
heavy water production, and uranium
isotope separation. Eventually it was assessed that nuclear fission would not contribute significantly to ending the war, and in January 1942, the
Heereswaffenamt turned the program over to the Reich Research Council while continuing to fund the program. The program was split up among nine major institutes where the directors dominated the research and set their own objectives. Subsequently, the number of scientists working on applied nuclear fission began to diminish, with many applying their talents to more pressing war-time demands.
The most influential people in the
Uranverein were
Kurt Diebner,
Abraham Esau,
Walther Gerlach, and
Erich Schumann; Schumann was one of the most powerful and influential physicists in Germany. Diebner, throughout the life of the nuclear weapon project, had more control over nuclear fission research than did
Walther Bothe,
Klaus Clusius,
Otto Hahn,
Paul Harteck, or
Werner Heisenberg. Abraham Esau was appointed as Hermann Göring's plenipotentiary for nuclear physics research in December 1942; Walther Gerlach succeeded him in December 1943.
Politicization of the German
academia under the
National Socialist regime had driven many physicists, engineers, and mathematicians out of Germany as early as 1933. Those of Jewish heritage who did not leave were quickly purged from German institutions, further thinning the ranks of academia. The politicization of the universities, along with the demands for manpower by the German armed forces (many scientists and technical personnel were conscripted, despite possessing useful skills), would eventually all but eliminate a generation of physicists.
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At the end of the war, the Allied powers competed to obtain surviving components of the nuclear industry (personnel, facilities, and
materiel), as they did with the
V-2 program.