Bulgaria had been drawn into the German orbit in the 1930s, and was bought over by territorial ambitions: the prospect of seizing Dobruja....
In March 1941, it became the last state to join the Axis, and German troops immediately moved into the country. On December 13, 1941, King Boris III needlessly declared war on the United States and Britain, though Bulgaria kept diplomatic relations with the Soviet Union. He calculated that this act of war might be a gesture of compliance with Nazi Germany, without requiring any engagements on the Eastern Front...
King Boris died suddenly in August 1943, prompting rumors that he had been poisoned by the Germans. His six-year-old son, Simeon, became King, and the Regency started to contact Britain and the United States about a Peace Settlement....The government tried to move to unconditional neutrality on the Swiss model, but the military situation did not really allow this attractive luxury....
On September 2, 1944, Stalin declared war on Bulgaria, and the government responded by delcaring war on Germany. Since this was intended mainly to impress the western Allies, the news was first spread through embassies, and the Germans at first did not know that another country had declared war on them and denied the rumors. The Bulgarian quest for Swiss-style neutrality had thus led the country to be at war with Britain, Germany, the Soviet Union and the United States.
At war with the US, Germany, the Soviet Union, and Britain. AT. THE. SAME. TIME. Nice job, Bulgaria.

