We March Against England - Operation Sea Lion 1940-41
by Robert Forczyk; Osprey

This 368 page title covers the period July 1940 to May 1941 when the invasion of Britain was, according to the author, a possibility. It is divided into the following chapters;

1. Strategic Setting
2. Improvising an Invasion Force
3. Diplomacy, Espionage and Intelligence
4. Kriegsmarine and Luftwaffe Capabilities
5. Countdown
6. British Anti-invasion Capabilities
7. Feasibility S-Tag 25.9.40
8. Isle of Wight Gambit
9. Siege Operations October 1940 to May 1941
10. Hidden Benefits - German Amphibious Capability
11. The Reckoning

and has been researched from German records held by the US Archives (maybe a tad one sided, especially the arse-covering reports written for the US Army by failed German officers in 1945-46?). Nevertheless the extent of work is prodigious and includes information not readily/easily available. Mr Forczyk has written 65+ books, the majority covering WW2 German subjects, so he presumably has developed a feel for this topic. Prior to his current career he served in US military intelligence so seems to be on firm ground with army related topics but much less so with those dealing with air forces ("inferior aircraft.....such as the DB-7 Boston"; "nor did the P-51 Mustang...have a successful career in the RAF", apparently not knowing it was designed to British requirements!). He has less to say on "matters maritime".
In Chapter 3 he raises the popular revisionist myth of "German anti-Nazi resistance" so beloved by US historians as a possible reason for Nazi failures (in reality it only emerged once the Germans were having the shit kicked out of them by the Soviets after Stalingrad and proved to be even more incompetent than the Nazis).

He is continuously critical of Churchill for making what he considers mistakes, not having a strategic plan in 1940 (he only became PM on 10 May 1940), spending all of Britain's foreign reserves on US equipment of dubious value (capitalism 101 as the US overcharged 200-300%) thus sending it bankrupt in 1946 and "flailing around" attacking every country perceived as a potential enemy (Darlan would not have surrendered the French fleet in 1940, as he didn't in 1943 - when it was clear the Nazis were losing and he was facing a Free French treason trial). He never seems to have heard "when you're up to your arsehole in alligators, you tend to forget you really wanted to drain the swamp". Churchill certainly made many mistakes during the war (early on he also had to contend the Nazi arse-lickers left over from Chamberlain) and Mr Forczyk thinks not negotiating with Hitler was one of them, even if only for a temporary ceasefire which would have allowed British forces to recover from Dunkirque. He completely disregards the fact the Germans would have been replacing the aircraft/aircrew and ship losses (prodigious and severe respectively) if that had happened, let alone the effect on the population, armed services and the Empire.

Like many US writers on WW2, the author comes across as somewhat bemused, if not actually disappointed, that the Germans failed to defeat Britain in 1940. Nevertheless this is an important work and is recommended to anyone with an interest in WW2 history.