pro Marxist-Leninist one party system socialist government
It was a quasi-absolute monarchy with parliamentary trappings.
The leader of the Government: Vassil Radev engaged Bulgaria to join the World War I
Bulgaria, like other countries in Eastern Europe, soon had a Communist government.
Vasil Radoslavov as executive of the government
The members of the Central Powersduring World War I were the German Empire, the Austro-Hungarian Empire, the Ottoman Empire and the Kingdom of Bulgaria, along with their assorted colonies.
Following World War II, Bulgaria was controlled by the Soviet Union.
Bulgaria was a constitutional monarchy during most of World War II with Tsar Boris III ruling with a Prime Minister and a Parliament. Prime Minister Bogdan Filov controlled the country with the Tsar Boris. They declared Bulgaria to be a neutral nation. I have provided a link for you below if you want to read more about Bulgaria during the war.
After the World War 2 Italy did have a democratic type of government.
Bulgaria
Which war, world war or Balkan war
Bulgaria fought on the side of Nazi Germany during the war.
There were many others. After all, it was a World war. Other countries aligned with the Allies included Mexico, Polish Government In Exile, Bulgaria, Greece, Tibet and so on.