What was the Role of Bulgaria in WW2?

Of the countries that fought alongside the Axis powers in World War II, Bulgaria was surely a special case. It was without a doubt one of the countries less committed to the war and to its own allies. Bulgaria didn't invade the Soviet Union and wasn't committed to the war against the Comintern. Why then did Bulgaria enter the war and what eventually became of it? Bulgarian military forces occupied with German consent parts of the Kingdom of Greece and Yugoslavia, which Bulgaria claimed on the basis of the 1878 Treaty of San Stefano. Bulgaria resisted Axis pressure to join the war against the Soviet Union begun on 22 June 1941, but declared war on Britain and the United States on 13 December 1941. The Red Army entered Bulgaria on 8 September 1944. Bulgaria declared war on Germany the next day. At the start of the war, like many other modern kingdoms, Bulgaria was a constitutional monarchy. As it stated its constitution of 1879, Bulgaria didn't have a noble class per se, other than the Tsar's royal family. It was at the time, actually, the society was with the smallest class gap in the region, something which complemented with a developed universal education system. Bulgaria was also one of the most ethnically homogenous societies in the Balkans. Nonetheless, despite such equality indicators, the local political climate during these first 20th century decades were agitated enough. As such, at the start of World War II, Bulgaria, despite being a constitutional monarchy, was actually a dictatorship, in which Tsar Boris III held all the power. As a monarch, Boris started his reign in 1918 by mostly staying out of politics. Yet, after a coup d'état against him in 1934 abolished political parties on recovering the power the next year, the Tsar, as a response to political instability and in order to maintain institutional security, made a coup d'état himself, becoming dictator of Bulgaria. Political parties were still banned, and even in 1938's election, political labels were forbidden. Prior to World War II, Bulgaria had a history of territorial loss. Its borders suffered heavily the kingdom's defeats, first in the Second Balkan War and shortly after in World War I. The treaty, signed between Bulgaria and World War I winning nations in 1919, made the Balkan country lose a third of its territory. The loss of these territories also meant for Bulgaria losing an important part of its economic production, like the tobacco fields in western Thrace that accounted for a large part of the country's production. To be accurate, Bulgaria's territorial loss started all the way back in 1878. That year, territories granted to Bulgaria by the Treaty of San Stefano, which gave the country a vast land extension, were cancelled only months after the Treaty of Berlin, in addition to taking away its recently gained autonomy from the Ottoman Empire. While the first treaty was motivated by Russia, looking for an ally in the Balkans, the second one was signed for the western powers, alarmed by the presence of a Russian backed-up state in the region. In this way, since then, Russians were seen by Bulgarians, if not as liberators, at least as friendly people to Bulgaria. At the same time, with the loss of these territories, Bulgarians adopted a sense of right over them. The answer then to why Bulgaria entered the war is simple yet complex. Territory. This doesn't mean that the conquest was in the agenda of Bulgaria. Having lost World War I, it had its army size limited, and it was a rather weak country, unable to become an actor in an international conflict. And yet, Bulgaria saw the war as a scenario in which it could recover the territory it had lost in the previous World War and in the Second Balkan War. Not to mention the fact that a great number of Bulgarians lived then in these territories, which facilitated their annexation. Then there is also a second question. Why did it choose the Axis? Prior to joining the Axis, Bulgaria received an offer of the USSR for obtaining a Yet Boris denied, as he feared it was at best a friendly forced occupation. On the other hand, due to its history of having a territorial dispute with them, Bulgaria was unable to see its neighbor countries in the Balkan region as allies, to rely on in defending against exterior threats. As such, as these countries chose to be allies of France in the United Kingdom, Bulgaria was less inclined to follow them. At the same time, although Italy was influential in Bulgaria to some extent, it was Germany who was indeed admired by its people. Since World War I, Germany became a relevant part of the Bulgarian economy, accounting for a big share of its importations and exportations, as well as its main weaponry Culturally speaking, Bulgaria received a great social influence of German scholars and intellectuals. Nonetheless, rather than becoming a part of the Axis as soon as the war started, thanks to British ambassador intervention, Bulgaria positioned then merely as neutral. In this sense, prior to entering the war, Bulgaria successfully recovered without making a single shot. Southern Dobruja, part of its former territory, in 1940. Neutrality ended in March 1941. Despite Boris's efforts, having the German army at the borders was intimidating enough to accept joining them. At the end of 1941, Bulgaria declared war to allies, resulting in the bombing of many Bulgarian cities shortly after, but specifically not to Russia, since it would have had to fight them given its proximity. At the same time, when Germany asked for help in fighting the Soviet Union, Boris III's argument that Bulgaria's hearts for this Slav country would not support fighting against its people. But this is not the only reason. Bulgaria wasn't a neighbor of the Soviet Union, and the Russians didn't make any aggression against them. Yet despite having joined the Axis and letting the Wehrmacht use their territory to invade neighbors, Bulgarian forces didn't take part in Yugoslavia's invasion, nor Greece's. Bulgarian troops only reached these countries after Germany had successfully defeated them. The same happened with Macedonia, and yet after Germany invaded these countries, Bulgaria didn't have a problem with getting some of their territories. But this alliance with the Axis was not meant to last. In 1943, with the fall of Mussolini, an allied invasion of the Balkans seemed imminent. All the while, Germany was unable to advance on the Oriental front. The tides of war were against the side Bulgaria had chosen, and by this point, Boris was probably already considering changing sides. That same year, Boris died just a few days after refusing Germany to attack the Red Army. The course of the war was, nonetheless, already decided. Bulgarian communist partisans were fighting against the Germans within Bulgaria since German invasion of the Soviet Union, and Bulgaria's role in the war as an Axis allied finished with the entering of Red Army troops in its territory in September 1944. The Soviet Union access to the country was followed by a purge of the country's political class. Those same communist partisans made a coup d'etat, finishing Bulgarian monarchy and taking the power to their own party. In this context, Bulgaria ended up declaring the war to Germany shortly after, and joining the Allies. Bulgarian troops aided the Soviets in fighting through Eastern Europe, not only in the Balkans, but in northern scenarios like Austria and Hungary. Looking at how Bulgaria treated its allies and enemies, we can only say that its participation in World War II was as calculated as it could be in order to fight the least and benefit the most in an extremely problematic situation. Only with this in mind could a country look out for being an ally of Germany and Russia at the same time. After the end of the war, Bulgaria had to return most of them. Although it conserved southern Dobruja, which was previously part of Bulgaria, but lost in 1913 after the Second Balkan War. Economically speaking, though the allies with Germany proven to be a wise choice in the long term. Under its guide, since the 30s, Bulgaria developed a modern agriculture economy, as well as a light industry, which helped the country in recovering after the war ended.