Could the Germans have invaded Britain in 1942?
Obviously, yes. Anyone can invade. Whether they have more than a snowball's chance in hell is an entirely different question.
I'm sure Hitler could have ordered all his remaining paratroopers (who survived the Battle of Crete) to fly over to Southern England in Ju 52 transport planes. Most of them would get shot down into the English Channel by gleeful RAF fighter pilots. It might be nicknamed Goering's Turkey Shoot.
But enough paratroopers would land to give the "Dad's Army" a great yarn to tell in the evening pub meet up.
The definitive wargaming of this was carried out in 1974 at Sandhurst, refereed by such luminaries as Galland (air), Ruge (naval), and Trettner (army) on the German side, and Foxley-Norris (air), Guerley (naval) and Gilbert (army) on the British side.
A unanimous "resounding failure", two invasion waves launched in late September 1940, and while the first was able to get ashore largely intact, the lack of local German naval and air superiority resulted in the second resupply and heavy equipment wave getting essentially destroyed - resulting in the invasion's defeat within a week. Even if a key assumption that Hitler wouldn't halt the continued bombing of London were reversed, the outcome was never in much doubt.
Cox published a book analyzing the war game Operation Sea Lion: Richard Cox: 9780891410157: Amazon.com: Books , a summary of which is available at http://mr-home.staff.shef.ac.uk/...
Perhaps if Hitler had not attacked the USSR and brought them into the war and had concentrated all of Germany's war efforts on the UK then it might have succeeded (by which I don't just mean launched and invasion but have eventually succeeded in conquering the country).
America also, of course, was at war with Germany by 1942, but if Hitler hadn't of declared war on the USA in support of the Japanese, then that might not have happened (and it's unclear how much effort America would have put into the "soft support" for the UK in those circumstances in the form of supplies and partial escorting of convoys in part of the Atlantic.
However, even given that scenario, it would still have been a tough nut to crack. Hitler would have had to put huge resources into both the building up of an invasion force and air attacks on the British war economy. As Germany lacked any strategic heavy bombers the might have been tricky, but a build-up of the U-Boat fleet would have helped too.
Of course the UK's defences were also bolstered at the same time - in 1942, the RAF was a far more formidable opponent than it was in 1940 during the Battle of Britain (and even more so if the emphasis hadn't been moved to building strategic bombers).
As it is, in 1942, Germany was in no position to launch any more invasions as it got increasingly bogged down in the war in the East, so we'll never know.
I should add that even if Germany had not attacked the USSR in mid-1941, they would still have had to put a lot more into their ground forces suited to a continental conflict as both Stalin and Hitler knew that at some point the two regimes would come into military conflict. So it might not have been possible to divert all those resources into building up the navy, invasion fleets, U-Boats and so on.
For many reasons, I seriously doubt the Germans could've successfully invaded and held any significant territory for long.
For multiple reasons:
- Britain had superior detection capabilities. With radar and the observer network, invading sea and airborne forces were likely to be spotted in sufficient time for defences to be ready and counter-attacks prepared. This is the primary reason why The Battle of Britain was won by a smaller airforce.
- Superior Naval forces by some margin. Britain had the world's most superior navy in 1940 and was more than a match for the Germans even including their U-boats.
- Superior airforce. The RAF was generally better trained, and whilst the opposites sides' fighters were evenly matched, the Spitfire has a tighter turn capability and the Hurricane had better survivability and quicker turnaround time despite being a bit slower.
- Superior tactics. Due to our unfortunate colonial history, and the fact we are an island nation, Britain has been involved in many many battles and many wars. We have experience and the battle scars so to speak.
- Superior intelligence. Britain's links to its allies, particularly Poland, aided in decryption of Enigma. Many of Germany's wartime communications were decrypted and ultimately led to Allied victory.
- Character. The Brits are a friendly people, but if you push us into a corner, we will always come out fighting. We will generally stand up for the underdog. I like to think we've learned the lessons of history in the main. Including our own mistakes.
Because this guy set up a brilliant defensive radar/human observer system...
They did. Guernsey in the Channel Islands. Technically, Guernsey conquered England in 1066, and still consider England a Guernsey ( Norman) terrtitory.
A comedy was made based on this, The Mouse that Roared, with Peter Sellers. Only they invade the US, hoping the US will win, and spend billions in Grand Fenwick ( Guernsey)
However, I evade your question, Hitler did not invade England because he felt the English were German ( they are), and felt that they would eventually join together. Many German sympathisers were in England, as in the US.
AN english german division was created in Germany, made up of English sympathizers, called the St George division ( or brigade)..not sure.. The royal family were german, and spoke german in buckingham palace into WW1. The unit wore the flag of St George on the sleeve, which is the English flag.
The point being, there was not a great philosophical difference between germans, brits and americans, not at the beginning of the war, anyway.