The Greco-Italian War, also known as the Italo-Greek War, was a conflict between Italy and Greece, which lasted from 28 October 1940 to 23 April 1941. The conflict marked the beginning of the Balkans campaign of World War II and the initial Greek counter-offensive, the first successful land campaign against the Axis powers in the war. The conflict known as the Battle of Greece began with the intervention of Nazi Germany on 6 April 1941. In Greece, the war against Italy is known as the “War of '40”
Italy had invaded Albania in the spring of 1939 and attacked the British Empire in Africa, completing the conquest of British Somaliland and began an invasion of Egypt in the summer of 1940 but could not claim victories like those of Nazi Germany. Benito Mussolini wanted to reassert Italian interests in the Balkans, feeling threatened by German encroachments (the Kingdom of Romania in the supposed Italian sphere of influence, had accepted German protection for the Ploiești oil fields in mid-October) and secure bases from which British outposts in the eastern Mediterranean could be attacked.
On 28 October 1940, after Greek prime minister Ioannis Metaxas rejected an Italian ultimatum demanding the occupation of Greek territory, Italian forces invaded Greece from Albania. The Greek army counter-attacked and forced the Italians to retreat. By mid-December, the Greeks occupied nearly a quarter of Albania, tying down 530,000 Italian troops. In March 1941, Operation Spring (Operazione Primavera), an Italian counter-offensive failed and on 6 April, Nazi Germany invaded Greece through Bulgaria and Yugoslavia, beginning the Battle of Greece.
On 12 April, the Greek army retreated from Albania to avoid being cut off by the rapid German advance and on 20 April, the Greek Epirus Army Section surrendered to the Germans. On 23 April, the armistice with Germany was repeated with the Italians, ending the Greco-Italian war. By the end of April, the Axis occupation of Greece had been completed by Italian, German and Bulgarian forces, with Italy occupying nearly two thirds of the country. The Greek victory over the initial Italian offensive of October 1940 was the first Allied land victory of the Second World War and helped raise morale in occupied Europe.
https://en.wikipedia.org/wiki/Greco-Italian_War
Adolf Hitler was not very pleased with Mussolini’s initiative to invade Greece which started The Balkans Campaign of WWII. You are Germany. Instead of being angry with Italy…do you decide to help Mussolini earlier in the campaign, intercede historically, or help later?