This article is from the soc.history.what-if FAQ, by Anthony Mayer anthonyemayer@yahoo.co.uk with numerous contributions by others.
Not with the existing situation in 1940: Germany lacked the necessary
resources to force the English Channel, and even transporting and
supplying ground forces of the necessary size would have been
difficult, probably impossible. Alison Brooks and Ian Montgomerie have
posted extended arguments to this effect; see their webpages (Question
19). A plausible Nazi defeat of Great Britain requires changing
something other than just going ahead with Sealion.
 
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