Did Russia annex Eastern Europe?
USSR was a continuation of Russia and inherited imperial ambition of its predecessors. Russia after 1922 did not exist as state, but it was a key state of USSR. Countries like Ukraine, Belarus, Baltic states, and Caucasus were part of Russian empire, some of them for centuries. Russia also controlled a part of Poland until 1918. Russia influence over Central Europe and Balkans was checked by Austria-Hungary, and Prussia/Germany. Austria tolerated Russian influence in Eastern Balkans, but considered western Balkan as its area of interest. Germany extended its influence into Balkans as well. The German influence over the region lasted till the end of WWII. Ukraine attempted to establish own independent state before 1922, but was conquered by Red Army during Russian civil war. Belarus never had strong nationhood ideas, and it is only Slavic country that lacked deep national identity and did not oppose Russian influence as did others.. Countries that were established after 1918 like Poland, Czechoslovakia were hostile to USSR and were ally of France. Hungary was a historical enemy of Russia and later USSR. Romania, Hungary, Baltic states, Finland, Slovakia, Bulgaria, and Croatia were German's ally during WWII and some of them fought against USSR. After 1945, the region became a satellite block against the will of the inhabitants and the government. It was colonization by one country that looted wealth and resource of all subjected states. USSR established collaborative governments, and eliminated opposition. Hungary, Baltic States, and Poland never accept it and USSR even set up leadership who often were not even a citizen of these countries (like Rokossovski in Poland). Eastern Europe opposed Soviet hegemony, but they were either invaded (Hungary 1956, Czechoslovakia in 1968), or threatened (Poland 1956-1970-1981), Romania, or Yugoslavia. Ukraine is unique case, as it has pro-Soviet, pro-Russian east, and independently minded western provinces. However, majority of Ukraine citizens do not want to be a part of Russia or USSR.
Why didn't Hungary and Finland declare war on the USSR with Nazi Germany at the same time like Romania and Italy?
Because Hungary was reluctant to enter the war. The Hungarian army was not configured to fight a war in Russia against one of the most powerful armies. It was designed to fight the neighboring countries’ armies in an attempt to retake the territories taken away after WW1. After the Soviet air force mistakenly bombed the Hungarian city of Kassa and Soviet fighter planes strafed a Hungarian train, the pro-war faction won in the National Assembly and Hungary joined the Germans.Finland had its war with the Soviet Union already and they were glad that they survived it. The least they wanted was another conflict. Finally they half-heartedly joined the invasion, but they did little more than guarding their own borders in a little obtrusive way.
What countries fought Russia during WW2?
Note: I am limiting this answer to "countries" or states. Invaded Poland., then The Axis: Germany, Italy, Japan, Hungary and Romania (Bulgaria was a member of the Axis, but refused to fight against the USSR. ) Puppet states (governments not recognized): Croatia, Slovakia, Manchukuo Then you have Finland, fighting the USSR in the Winter War of 1939-40, then the Continuation War of 1941-44 . These conflicts are concurrent with WW2. So Finland was a "co-bellegerent"
What did Bulgaria do in WWII while allied with Germany?
First off, Bulgaria was in pretty rough shape between the wars. Her biggest trading partners were Germany and Austria, and they were crushed after WW1. The Russians were now the USSR, and as Bulgaria was a monarchy (formerly closely tied with the Czars of Russia) that made them a big mean enemy right next door. When WW2 began, Bulgaria’s choices were pretty limited, and stuck between the Nazi rock and Stalin’s hard place, the Bulgarians allied with Germany.King Boris of Bulgaria didn’t have many troops, and those he did have would have been considered 3rd rate by German standards. Poorly equipped and trained, Bulgaria had no air force, no tanks, and ranked somewhere below the Italian and Romanian troops in Germany’s allied contingents on the Eastern Front.What Boris did, that no other leader in Nazi orbit had the courage to do ws to save the Jews of Bulgaria from the Holocaust. The details are argued about, and the truth is now obscured by history, but the fact remains that Bulgaria’s 50,000 + Jews all survived the war. Despite incredible pressure to deport them to the Death camps, Boris, and elements of his government resisted the Germans and preserved the lives of those innocents. Boris was likely poisoned by the Nazi’s soon after his last meeting with Hitler, when it was clear the war was going badly for the Germans. Hitler never forgave Boris for protecting the Jews, and used a poison common to other Nazi assassinations of high level leaders. No direct proof of this remains, but there’s enough circumstantial evidence to make it a more than likely reason for his premature death just 48 hours after returning from Germany.Bulgaria would be over run by the Soviets, and totally hammered (and sickled) into a communist state, which it remained until the 90’s. That was the price she paid for her allegiance to the dictator. The long untold story of Boris, and the thousands of lives he saved, is still waiting to be fully told.