British independence is fundamentally tied to the independence of other neighbouring European states from other great powers.
This is the basis of 500 years of British foreign policy since the breach from Rome.
And had the Germans done only a little better, British independence would have been a matter of *surviving* in the face of other European states being consumed by the Reich. It not that unlikely that had Dunkirk gone a bit different, Britain might have sued for peace.
After the fall of France, the German Army High Command (OKH) planned the invasion of the British Islands by landing over forty divisions. After collecting 2,400 barges, 471 tugs and 155 transports from the invaded countries, the planners were informed that the Kriegsmarine had suffered great losses in Norway, that it had only three cruisers and four destroyers to escort the improvised invasion fleet and that at the other side of the English Channel, that was mined, the Royal Navy had eight cruisers, 54 destroyers and 700 small coastal motorgun boats, corvettes and minesweepers.
In the face of the hesitations of the OKH, the
Oberkommando der Luftwaffe (OKL), poorly informed about the British radar system, about the number of aircraft of the Fighter Command and on the ability of British industry, decided to start an attrition campaign over the territory between London and the south coast of England. Its objective was the annihilation of the RAF fighter force, which had already lost 195 Hurricanes and 67 Spitfires in France, so that it could not oppose an airborne invasion. The Luftwaffe, conceived as a tactical air force specialized in supporting the operations of the Wehrmacht, was not prepared for this kind of strategic war as it lacked four engine heavy bombers.
During the fighting in Poland the Germans had lost 285 aircraft, 260 in Norway, 317 in the Netherlands, 432 in Belgium and 1,279 in France. One third of the total were Junkers Ju 52 transport aircraft that could had been used in the invasion project. Outside combat operations, the 'usual' attrition rate of the Luftwaffe was 85 aircraft destroyed and 96 damaged every month, a third of them in accidents.
By the end of July 1940, the Germans had 769 medium bombers, 656 single-engine fighters, 168 twin-engine fighters, 316 dive bombers and 100 reconnaissance serviceable airplanes in France. The Fighter Command only had 650 fighters at that time, but the British aeronautical industry had already accelerated production and on 13 August, the day of the German offensive, it already had 1,381 fighters.
At the end of August, the German intelligence services estimated that 800 British fighters had been destroyed, with an attrition rate of 100 aircraft per week. They believed that by the end of September the Fighter Command would have been neutralized, but in fact it still had 750 fighters capable of fighting at that time. In its vised attempt to achieve air superiority the Luftwaffe lost 1,887 aircraft. The price of British survival were 1,023 aircraft of the Fighter Command, 376 of the Bomber Command and 148 of the Coastal Command.
France had only the Maginot Line for its defence, but the British Islands were protected by eight barriers that the Germans did not manage to cross. The English Channel, the Royal Navy, the Chain Home with 21 radar stations, the Anti-Aircraft Command with 350,000 personnel, 1,340 heavy guns and 370 low level guns, the Balloon Command with 40,000 personnel and 1,400 balloons, the Royal Observer Corps with 30,000 personnel, the Fighter Control System force multiplier and the Hurricanes, Spitfires, Defiants and Blenheims of the Fighter Command.