In the summer of 1940--after the Nazis crushed France and defeated Belgium--all Britain prepared for a German invasion. English forces stood on the Channel coast, waiting, but though the Luftwaffe bombarded Britain day and night, occupying forces never arrived. Why did they never attack this nearly defenseless island? Look through German eyes and get to bottom of the indecision that in the end may have cost them the war.
It was refreshing to find a treatment of this subject from the German perspective. British and American authors tend to characterize Sea Lion preparations as a haphazard affair that was doomed to failure if the Germans had been crazy enough to try and invade. Kieser addresses these issues in detail, leading one to understand that the war in 1940 was a lot different (and newer) than it was in 1944. Accordingly, comparing Sea Lion to D-Day is not entirely instructive. Add to this the prowess of the German war machine, especially its planning apparatus, and one can imagine circumstances where an invasion could have presented serious difficulties for the British.