Sealion: Lost Opportunity or Disaster Averted? Hitler's Germany had achieved an unimaginably rapid victory over France in the spring of 1940 to gain complete domination of western Europe.

Britain alone held out, secure—or so it seemed—behind the moat of the English Channel. German planners had already made preliminary studies for an invasion of the island, but these were more in the nature of contingency plans than serious operational proposals. That changed in July when Hitler called for an invasion—Operation Sealion—to be carried out that fall.

This issue will examine the inception, planning, preparations, and likelihood of success. The invasion will also be placed in the larger context of the war, to include the possibility the invasion was a bluff, either to push Britain to the negotiating table or distract the Soviet Union, plus proposed alternatives for defeating Britain such as the aero-naval blockade of Britain and Grand Admiral Raeder's Mediterranean strategy.


Released: 30 June 2026