This is going to be long enough that I will split it into two parts.
Fer Fal had an interesting, but I believe incomplete, discussion of what caused the decline of Argentina. I also came across an interesting discussion of the collapse of the Soviet Union at Marginal Revolution. This is conveniant because it will allow me to cover the genesis to two popular post economic collapse non-fiction books: Surviving the Economic Collapse and Reinventing Collapse: The Soviet Example and American Prospects
Both countries collapses hinged on an overabundance of commodity production relative to an underdeveloped general economy. A lack of self sufficiency or at the very least a more rounded export trade caused a trap where fluctuations in export values caused a collapse.
Argentina suffered from the Dutch disease. The name comes from what happened to the Dutch economy after the discovery of natural gas in 1959. To simplify, when a company is able to export a lot of natural resources, often using a relatively small portion of its labor or capital, it begins increases its spending to match this income. Other parts of the economy are crowded (through the high exchange values)by the boom in commodities and consumption. Too much money comes in and it drives up the cost of local goods, while reducing the prices of imports. Local producers and manufactures cannot compete with the influx of imports. This is not generally a problem except that the supply of the commodity often begins to run short, or in the case of both the Soviet Union and Argentina, prices drop from the boom periods.
Let us start with the Soviet Union.
The Soviet Union destroyed its agricultural base starting in the1920s to force their economy to industrialize. They succeeded in industrializing, but at the expense of needing to import large amounts of food.
For a time period, the Soviets were able to ignore the inefficiencies of communism because as a follow-on industrializer they were able adopt efficient methods by simply copying what the West had done: innovation was not required. The policies of terror also kept everyone moving. However, once the gains from this industrialization had been gained (and they rebuilt from WW2), inertia set in. They needed foreign exchange (money) to pay for their food imports, but their industrial base had nothing to sell that the food producing countries wanted: except oil.
So long as the Soviet Union was able to sell oil, they were able to cover over the problems with the rest of their economy. Although the command economy with default rationing was able to keep some of the difficulties in check, they tended to stymie development in the non-oil portions of the economy even further.
The timeline of the collapse of the Soviet Union can be traced to September 13, 1985. On this date, Sheikh Ahmed Zaki Yamani, the minister of oil of Saudi Arabia, declared that the monarchy had decided to alter its oil policy radically. The Saudis stopped protecting oil prices, and Saudi Arabia quickly regained its share in the world market. During the next six months, oil production in Saudi Arabia increased fourfold, while oil prices collapsed by approximately the same amount in real terms.
As a result, the Soviet Union lost approximately $20 billion per year, money without which the country simply could not survive. The Soviet leadership was confronted with a difficult decision on how to adjust. There were three options--or a combination of three options--available to the Soviet leadership… dissolve the Eastern European empire and effectively stop barter trade in oil and gas ,…drastically reduce Soviet food imports by $20 billion, the amount the Soviet Union lost when oil prices collapsed,…implement radical cuts in the military-industrial complex.
Unable to realize any of the above solutions, the Soviet leadership decided to adopt a policy of effectively disregarding the problem in hopes that it would somehow wither away. Instead of implementing actual reforms, the Soviet Union started to borrow money from abroad while its international credit rating was still strong. It borrowed heavily from 1985 to 1988, but in 1989 the Soviet economy stalled completely...
The money was suddenly gone. The Soviet Union tried to create a consortium of 300 banks to provide a large loan for the Soviet Union in 1989, but was informed that only five of them would participate and, as a result, the loan would be twenty times smaller than needed. The Soviet Union then received a final warning from the Deutsche Bank and from its international partners that the funds would never come from commercial sources. Instead, if the Soviet Union urgently needed the money, it would have to start negotiations directly with Western governments about so-called politically motivated credits.
In 1985 the idea that the Soviet Union would begin bargaining for money in exchange for political concessions would have sounded absolutely preposterous to the Soviet leadership. In 1989 it became a reality, and Gorbachev understood the need for at least $100 billion from the West to prop up the oil-dependent Soviet economy. From The Soviet Collapse: Grain and Oil by Yegor Gaidar
The oil crisis highlights the essential fault in the Russian economy. The real Russia that had for many years been hidden from public view was deficient in manufacture and stuck with an aging capital stock. It was primarily a supplier of natural resources such as oil, gas and metals. Most of their manufactured products largely failed to sell on the world market because of their poor quality and lagging technology.
Oil is Russia's largest and most important natural resource but there's a long list of others, including reserves of nickel, copper and cobalt, and iron. The demand for these commodities is tied to the growth and stability of the world economy and subject to volatile price changes, big swings up and down and back again, following the same path as oil prices.
The importance of commodities to Russia is made clear by the simple fact that they comprise 70 percent of her exports and provide 30 percent of the national budget. From the Dick Wilson’s review of Yegor Gaidar’s Collapse of an Empire, Brookings Institute.