As the sky battle raged between the Royal Air Force and German bombers and fighter planes, determined to pound England into submission, another battle unfolded in English territorial waters. The plan Hitler had adopted to defeat Britain rested not so much on an invasion across the English Channel (which, in fact, would have been the ultimate solution if all else had failed), but on the strangulation of British trade.
On the eve of the advance of the German armies, motor torpedo boats, known as E-boats, made their appearance.
These torpedo boats pushed their bases to Cherbourg during the second half of June 1940. Their targets were coastal convoys. They also had the mission of laying offensive minefields in front of English ports. Large-scale air attacks against convoys and against ports also claimed a large number of victims among the English troops. These attacks aimed only to hit the boats without fighting them, they paralyzed a large number of British buildings. Several months of fierce and incessant skirmishes were to elapse before the enemy was held in check and the coastal trade could resume its course in relative safety.
It was also necessary to protect England against a possible invasion by sea. On the other side of the Channel everyone was expecting such an eventuality during the summer and autumn of 1940. would not have been a great novelty. The Royal Navy, once again, retreated to its traditional methods of defence, tried and tested by centuries of experience. These methods were based on the watchful surveillance of the invader by flotilla vessels—formerly sloops, cutters, and gunboats; in 1940, destroyers, torpedo boats and gunboats. Behind these, in the ports of all the coasts, east and west, watched the boats of greater power, immediate support of the defense, formerly frigates, today Cruisers . And behind these, always, was the decisive backup—the immense force of the battle fleet which was to sail south into action as soon as the invading forces got under way.
Beyond the waters of the English Channel stood Hitler's army in 1940, just as the armies of Napoleon, those of Louis XIV and Philip II of Spain had risen before. Against all these men and their dreams of conquest had risen the English navy. Against Hitler and his own fantasies, the English navy would still stand up. But days and weeks passed. While the means of transport withdrawn from the inland waterways (which greatly crippled local commerce) were still quietly moored in the Channel ports, the Lords of the British Admiralty might have echoed the words of the Count of Saint-Vincent who said, one hundred and fifty years earlier, that "when it comes to a military problem, one should hesitate before expressing the slightest opinion concerning an invasion as such". All they knew then was that the invasion "could not come by sea". Norway and the evacuation of Dunkirk, among others, there was an obvious lesson:ships could do nothing in waters dominated by enemy air forces. The most effective weapon to fight the Axis forces - Italy had joined the conflict when France fell - remained the blockade. To maintain the effectiveness of this weapon, it was necessary to continue to hold the circle of maritime power drawn around Europe. This circle, however, had to escape the planes that used the recently acquired airfields in Norway, Denmark, Holland, Belgium and France. Britain, now outflanked to the south and east, had to watch carefully, north and west, if she was not to be defeated. So she extended her maritime power towards Iceland, as well as towards the coast of Greenland, through the Denmark Strait. To the west it joined the Atlantic from Northern Ireland, then spread a great arc southward to Gibraltar and Freetown in West Africa. To complete the circle, the Mediterranean Fleet held the eastern basin from Malta to the coasts of Greece.
The Axis forces were therefore enclosed in this tenuous circle. They had to cross this barrier if they wanted to reach the raw materials held by the rest of the world. No barrier, however, would have been strong enough to contain the German warships. Nothing either, could forbid the U-boats the door of the oceans. But despite everything, the English managed to strangle almost all of this maritime traffic, without which the two Axis dictators could not win their war.
They had to hold this barrier, which, if a decisive victory were to be won by England, could serve a double purpose. It was not only a question of strangling the maritime trade of Germany and Italy; it was also necessary, while isolating the two powers, to safeguard the slow development of the resources and the forces of Great Britain, until the day when its strategy would be able to become not only defensive but also offensive. to bring to England all the oil, steel, tanks, guns, planes and ammunition without which the only future that remained was defeat. It was also necessary to bring from the dominions and the colonies, and later from the United States, the men who were one day to join the armies destined to carry the war on the European continent. It was finally necessary to be able to send the troops, the weapons and the ammunition necessary to the other theaters of operations, those of the Middle East and, later, those of the Far East.
This task, in these months of the summer of 1940, seemed insurmountable, especially since we had suffered so many losses during the operations in Norway and Dunkirk, and since, on the other hand, many ships were still immobilized in the English Channel. to prevent the invasion of England. Where, in 1939, it had been possible to provide each convoy with an average of two escorts, in 1940, this average had just been reduced by an eighth per convoy. In addition, submarines that began to use French and Norwegian bases could now shorten the journey they had to make by 1,000 miles or even more to reach their patrol areas, allowing them to operate considerably farther out into the Atlantic, often well beyond areas where convoys could be escorted. The first was occasioned by the occupation of Iceland and the Faroe Islands by British troops. These islands were dependent on Denmark, but when this country was invaded by Germany in April 1940, England quickly seized them so that Hitler could not claim them.
Iceland was particularly well situated to serve as a base for convoys on the Atlantic routes. It was to allow convoys coming either from England or from Canadian ports to be escorted much further. There was no question of using it immediately because it would take some time to set up, but in the future, undoubtedly, it would offer significant advantages.
The other light was brought about by negotiations undertaken by Churchill and Roosevelt. The United States undertook to cede to England a fleet of 50 old destroyers in exchange for certain bases in Newfoundland and the West Indies. These destroyers, of outdated type, were to be quickly overhauled and re-equipped in American shipyards:they were then to be made available to the English and Canadian navies, where they would be used to increase the number of escorts, while waiting for the new constructions to be able to join. the fleet.