USSR
I am no expert, but I can give you a generalization.
The USSR stands for Union of Soviet Socialist Republics. The greatest of which was the R.S.F.S.R., or the Russian Soviet Federative Socialist Republic. In other words, it was what we call Russia today. There were other states in the USSR such as Lavita, Lithuania, Estonia, Ukraine, Belarus (Bellarussia), Kazakstan, etc.. 15 republics in all. I assume that you want me to focus on Russia (RSFSR), and not any other part of the Union in particular.
To understand the political system of the communist government in the USSR, you must first understand their ideals. Communism (marxism) believes that the government should be run by councils of intelectuals. These councils were called "Soviets" by the Russians. Their might be a soviet for every factory, or every collective farm. The members of the soviet would be totally versed in the communist doctrine and would therefor be good people. The many soviets would all vote to decide local matters, and they would elect a leader to represent their soviet in a larger soviet that has a greater territorial jurrisdiction. Eventually at the highest level of government you would have one Soviet with one leader who would conduct the affairs of that soviet. Thus the name of the nation makes sense.
The USSR was first run under a Council of people's commissars under Lenin. The Council had a Premier (chairman of council of ministers/commissars). Lenin and Stalin were Premiers.
At some point the USSR also created a bicameral legislature. There was a Supreme Soviet, which had 2200 members. There was also the Central Comittee (Stavka) which had 300 members who proposed all of the laws. In theorey, the Supreme Soviet was the second highest legislature, and the Central Comittee was the highest branch of the government with the most power. But, because by law (and according to marx), all members of the government had to be from the same party, the communist party, the party had all of the power.
The party was controled by the politburo (replacing the council of commissars). The politburo had from 12-15 members. The members were usually very old and conservative. The politburo chose replacements when a member would be excused (gotten rid of), retire, or die. The Politburo voted on all replacements. The Politburo had control of the KGB(NKVD) secret police, and thus had all of the power. They told the Central Commitee what to do and the Supreme Soviet was nothing more than a ruber stamp.
Some of the central principles behind communism are economic equality, work for everyone, classless society, union of workers, farmers and intelectuals, etc... In reality, the USSR was one of the most rigid class systems in history.
When the communist revolution swept through Russia, reforms and executions began to take place. Workers in some places took control of the factories, and farmland was divided up. Now, when you have economic equality, people will argue about what to do. Who gets to use the horse and wagon at what time? Should money be divided by the community according to each working farm, or size of family? Should a new technique be implimented to make the factory work more efficiently? Who digs the ditch, and who milkes the cow? etc... This results in chaos, imbitterment, and lack of motivation.
Now, people must work, and they must work together, or everyone will starve to death. So the Red Army stepped in and said, "This is how it's going to work." And everybody listened because the Army has guns. But now look what has been done: You have the people with guns telling everyone else what to do. You sudenly create a society with at least two classes. Those with guns, and those without guns. Communism dies on the spot.
As you might expect, the people incharge of the army abuse thier power. They make sure that they get the nice homes, better food, and all sorts of material wealth. They also order those beneith them to spy on everyone else. They want to make sure that nobody else in the Army lower than them will take power from them. They have people killed who are ploting against them. There develops an entire pecking order in the government. But on the whole, the government leaders do what the army wants them to do.
When Stalin becomes leader of the government however, he goes on insane rampages of terror. He starvs and kills millions of people who are of certain ethnic groups inside the USSR. He is afraid that any ethnic group outside of the Soviet realm might rise against him and resist his attempts to control them. Once Stalin concentrates his power, he launches a set of purges in the military to make it totally loyal to him. He uses the secret police to spy on all sectors of society. Stalin launches the 5 year plans to modernize Russia. The people of Russia become virtual slaves.
After WW2, Stalin gained control of many nations in central and eastern europe. He set up communist, Russia-freindly governments in all of those nations, and set up branches of the secret police in those nations as well. Stalin also had every piece of machinery, and every piece of wealth possible moved from East Germany to the RSFSR. This helped to augment the distruction of WW2 battles in Russia.
Instead of improving the nation, the USSR and the its satelite nations built weapons as if they were still at war. The USSR created a Warsaw pact with the nations it controled to defend against NATO, created by the US. THe USSR built tanks, migs, subs, and launched a space program. They soon acquired the nuclear bomb and began mass-producing those as well. They would build weapons in huge numbers, and often would continue to build and keep up obsolite weapons. It was difficult to stop a weapons factory because if you did, you made enemies with the general in charge of that factory.
This wasted alot of money that could have been used for better things. Housing, food, and the standard of living remained poor. Stores that did have any items to sell were closed to most. People not in the communist party had no rights. Only some of those who were in the communist party had the right to enter certain stores. There was a very complicated system with luxury items. Anybody could buy a car, but very few had the money to buy a car. Musicians and scientists recieved more luxury items then workers. Generals and party officials were even better off. As a matter of routine, materials/products from Soviet block nations were sent to Russia, and little was sent from Russia to those nations.
No one was allowed to leave any nation under control of the USSR without permission. You were not allowed to travel in the USSR or its satelite nations without papers. Those papers were only given to people with connections. There was no freedom of speech.
From an early age, bassed on testing, people were assigned occupations for thier whole life. You had no freedom of employment. Only the select few recieved more than a highschool education.
By the 70s, the system began to fall apart. In 1974 (perhaps it was 1975) Richard Nixon went to China. China began to trade with the US, and turned its back on the USSR. Russia could no longer buy chinese products. Inflation skyrocketed along with shortages of every kind. In 1980, the Russian army went into Afghanistan at the request of a pupet communist regime, to help it fight the rebels. The US aided the rebels, and Russia lost alot of money and people in Afghanistan.
When Mikhail Gorbachev took control in 1985, he tried to adress these problems. He tried to institute economic reforms, to help get the USSR back on its feet. I think it was called paristrokya. It failed however, because there was fierce oposition to it in the government and military. People would not impliment the reforms. Gorbachev realized that economic reform wouldn't work without political reform. Gorbichev then introduced Glassnost (openness), or freedom to debate and speek about politics.
At the same time, even the standard of living for the KGB and upper echilons of the system began to fall apart. Even the KGB leaders had to give thir kids sub-standard cars. They knew that the system wouldn't last much longer.
In the US, Ronald Reagan began unveiling a plan called Star Wars. He wanted the US to create a satellite defense system against the United States. It would have cost the US trillions, but it would have made Russia militarilly powerless. The Russians looked at the plans, and had their best scientists analyze it. They concluded that if it was created, the USSR had neither the technology, nor the funds to counter it with a new weapon. At that point they knew the cold war was lost. For if the US could be immune from Russian attack, then the USSR's hold over Europe and would weaken because people nations would turn to the US for help, and the USSR would be powerless. Starwars was never created, but it was a bluf that worked.
In 1989, East Germany declaired that their would be a change in emigration policies, and people immidiately began flocking to the Berlin Wall. They took it upon themselves to take down the wall when the Eastern German soldiers didn't stop them. Soon, every warsaw pact nation broke away and the USSR left Afghanistan. Boris Yeltson led the movement to disolve the soviet union in the supreme soviet. Gorbichev slowly allowed some of the 15 republics in the USSR to break away, but the hardliners were still fighting against this. Gorbichev left to a resort home on the black sea so that he wouldn't have to take sides.
A group of generals and KGB surrounded his home and put him under house arrest because he wouldn't join them in a coup d'etat (blow against the state) These harliners also sent the army into moscow to try and take the reins of power. Yeltson however, convinved the army not to follow those orders, and the army remained loyal to gorbichev. Gorbichev was realesed from his home and the conspirators turned themselves in. Gorbichev went back to moscow and created a council with himself and Yeltson to reform the government. Yeltson however, created a new government in 1991 and the USSR ceased to exist. Yeltson was elected president and Russia became a constitutional republic.
The economy only got worse, however. People smuggled millions from Russia and fled the country on multiple occassions. The US sent millions in aid to Russia, but it did little good. The ruble last I checked is very low. The adverage hourly wage in Russia is less than $0.50 in American terms. The factories are old and make little profit. Russia is starting from scratch in most cases.
In 1993 When the communists in Parliament refused to give up their seats to new elections, they blocked the parliament building so that nobody could enter. Hundreds of their supporters raillied arround them. The communist party wanted to maintain thier position in parliament eventhough the people wanted new representatives. Yeltson called in the army and ordered them to open fire on the parliament building. Many were killed and 1,500 were wounded before they surendered. The communist party has never reared its ugly head in russia since. Russia today is a growing republic politically speaking. They even have a "none of the above" option for the presidential election. I would sure like to see that on the US balot. In 1995, Yeltson released from jail some of the original leaders of the coup against gorbichev to help heal the nation.
On a side note, durring the Tienimen Square massacre, Xao brought in retired members of the Politburo to swing the vote in favor of his side so that they could crush the protesters in the square. technically illegal as far as standard communism goes, but not without Soviet Precident.
