What difficulties did the United Kingdom and United States pose to Hitler's military strategy?

Answer 1

Great Britain and France declared war on Germany in 1939, forcing Germany to fight them after the conquest of Poland. Though Germany defeated them, Britain still controlled the sea lanes around Europe, denying Germany access to strategic supplies such as oil. Britain also waged a powerful aerial campaign against Germany, causing heavy damage to Germany's factories and bases. Because Britain is separated from Europe by the English Channel, Hitler could not conquer Britain.

Britain also fought Germany in Greece and North Africa, and provided supplies to the Soviet Union after Hitler invaded there in 1941.

The U.S., with its enormous industrial capacity, provided lavish supplies to Britain and the Soviet Union. U.S. war production was several times greater than Germany's. Soon German troops were outnumbered and outgunned.

The U.S. joined the British air war on Germany. Britain was the untouchable forward base for attacks on Germany.

Britain and the U.S. invaded Italy in 1943. Britain and the U.S. built up an immense army in England. In 1944 they invaded France, adding to the already severe pressure on Germany from the Soviet army. Hitler could not put up enough force to defeat the British and American armies, which marched across France into Germany to meet the Soviets.

Just a wee note - the BEF was forced to retreat from the continent after Armee Guppe Kliest (more particularly XIX Panzer Korps) broke the French line at Sedan on the River Meuse., and reached the Channel near Abbeville. British troops actually did very well in 1940 - inflicting severe losses on a number of German formations, and, with the exception of 51 Highland Division which was unable to retreat, no complete division was destroyed by the Germans.

The ongoing resistance of the United Kingdom, its Dominions, Empire and Commonwealth (Canada, Australia, New Zealand, the Indian Sub-Continent, East and West Africa including the peoples of Kenya, Uganda, Nigeria, Sudan, and so forth, South Africa, Rhodesia (now Zimbabwe)) meant that as Italy was in the war the British were able to force a repetitious series of defeats not on Germany - but on its weaker Ally. Within 1 year of entering the War in June 1940, Italy lost control of its Abbysinian empire (Ethiopia mostly), had a big chunk of its fleet sunk or crippled, and lost much of its Libyan possession to the British.

That, plus British aid to Greece (invaded in late 1940 by the Italians) meant that Hitler found it desirable to divert significant resources to removing British forces from bomber range of the critical (to the Axis) Ploesti Oil Fields. The diversion of 25-35% of Germany's power into the Balkans in 1941 can be seen to have slowed the launching of Operation Barbarrossa - which drew The Soviet Union into the war as Britains sole beligerant ally on 22/6/1941.

At the same time, the vaunted German Navy was busy sinking ships using submarines - but only in areas in which the Royal Navy had too few air and surface escorts (oddly enough not really on the North Atlantic run despite propaganda to that effect at the time). Meanwhile, the British Blockade on Germany cancelled a variety of key weapons programmes (mostly needing rare super hard metals not available in quantity within German controlled Western Europe).

The diversion of effort caused by Britain probably helped slow the invasion of Russia - and by giving hope to the enslaved peoples of Europe led the world.