What Happened To The Red Army When The Soviet Union Collapsed

How close was the Soviet Union to collapsing in 1941?

I would say 'not at all close'.  It may well be true that Stalin suffered some kind of psychological collapse following the invasion in 1941, but Stalin was not the Soviet Union. While the Nazi armies scored major successes against the Red Army in 1941 and captured large numbers of prisoners,  it is worth bearing in mind that by the end of that year, none of their strategic targets (Leningrad, Moscow, or the  oilfields of the Caucasus) had been captured.  And none of them ever were.  When Soviet intelligence confirmed that the Japanese were not planning to attack the Soviet Union in the East in 1941, the Soviets were able to transfer 18 divisions, 1,700 tanks, and over 1,500 aircraft from Siberia and the Far East to the Western front . In the Battle for Moscow that followed, the Nazis suffered their first significant defeat in a 'set-piece' battle.The idea that the Soviets would collapse easily or were even close to collapse was one of the fatal mistakes informing Hitler's Operation Barbarossa. I'm surprised that it still persists.  The Soviets mobilized their population in support of the war effort far better than Nazi Germany did.  They out-manufactured Nazi Germany by a massive margin, particularly in the production of armoured vehicles  (Soviet combat vehicle production during World War II / German armored fighting vehicle production during World War II)., and they had a better-developed war-fighting stragtegy in their 'Deep Battle' concept  (Soviet deep battle) than the Nazis ever achieved.WW2 cost the Soviets over 20 million dead and 1941 was certainly a low point, but their command and control systems and their economic infrastructure were too strong for the Nazis.

How were the republics of the Soviet Union formed after the collapse of the Russian Empire?

To put it simply, the Russian communists controlled those areas. When the Russian Civil War ended in the early 1920s, most of what was the former Russian Empire was absorbed into the newly formed Union of Soviet Socialist Republics. Poland, Lithuania, Latvia, Estonia, and Finland were the only parts of the old Imperial Russia that got away with independence, along with a few territories that were absorbed by Romania and Turkey. Originally, there were just four Soviet republics, Russia, Ukraine, Belyorussia (Belarus), and Transcaucasia. These republics were meant to represent a significant ethnic group, like Russians in Russia and Ukrainians in Ukraine. Through the 1922 Treaty on the Creation of the USSR, these republics formed the first communist nation by sending their “representative” delegates. Also remember many of these republics were reconquered by the Red Army during the Civil War. During the next 34 years, more member states were created or annexed. Between the late 1920s and the mid-1930s, the Muslim regions in Central Asia were created into the present borders of Kazakhstan, Kyrgzstan, Uzbekistan, Tajikistan, and Turkmenistan. In 1936, Transcaucasia dissolved into the current borders of Georgia, Armenia, and Azerbaijan. By the end of World War 2, the Baltic states of Lithuania, Estonia, and Latvia were annexed by the Soviet Union and the borders of Russia, Ukraine, and Belyorussia expanded westward into Poland, German East Prussia, and Romania. At the same time, Soviet Moldova was created out of the former region of Romania called Bessarabia. In the Northern region of Soviet Russia, Karelia, a region with a high Finnish population, also was created as a Soviet republic. In 1956, Soviet Karelia merged with Soviet Russia after significant improvements in relation between the USSR and Finland. Yeah I know there is a Little extra information, but each republic has its own unique story to tell.