German Blitzkrieg, Italy declared war on France and Britain on 10 June 1940, fulfilling its obligations of the Pact of Steel. Italy hoped to conquer Savoia, Nizza, Corsica, and the African colonies of Tunisia and Algeria from the French, but this was quickly stopped when Germany signed an armistice with the French commander Philippe Petain who established Vichy France which retained control over these territories. This decision by Nazi Germany angered Mussolini's Fascist regime. The one Italian strength that concerned the Allies was the Italian Royal Navy (Regia Marina), the fourth-largest navy in the world at the time. In November 1940, the British Royal Navy launched a surprise air attack on the Italian fleet at Taranto, which crippled Italy's major warships. Although the Italian fleet did not inflict serious damage as was feared, it did keep significant British Commonwealth naval forces in the Mediterranean Sea. This fleet needed to fight the Italian fleet to keep British Commonwealth forces in Egypt and the Middle East from being cut off from Britain. In 1941 on the Italian-controlled island of Kastelorizo, off of the coast of Turkey, Italian forces succeeded in repelling British and Australian forces attempting to occupy the island during Operation Abstention. In December 1941, a covert attack by Italian forces took place in Alexandria, Egypt, in which Italian divers attached explosives to British warships resulting in two British battleships being severely damaged. This was known as the Raid on Alexandria. In 1942, the Italian navy inflicted a serious blow to a British convoy fleet attempting to reach Malta during Operation Harpoon, sinking multiple British vessels. Over time, the Allied navies inflicted serious damage on the Italian fleet and ruined Italy's advantage over Germany. Continuing indications of Italy's subordinate nature to Germany arose during the Greco-Italian War; the British air force prevented the Italian invasion and allowed the Greeks to push the Italians back to Albania. Mussolini had intended the war with Greece to prove to Germany that Italy was no minor power in the alliance but a capable empire which could hold its weight. Mussolini boasted to his government that he would even resign from being Italian if anyone found fighting the Greeks to be difficult. Hitler and the German government were frustrated with Italy's failing campaigns, but so was Mussolini. Mussolini, in private, angrily accused Italians on the battlefield of becoming "overcome with a crisis of artistic sentimentalism and