Following the extraordinary people power uprising that toppled the government of Ukraine, and after weeks of protests in Caracas, Venezuela’s capital, many are asking, “will Venezuela be the next Ukraine”?

There are asking the wrong question. The question is, will Venezuela be the next Iran?

Resource prices and political risk have long been correlated. When resource prices go up, governments tend to seize the assets of natural resource investors, whether through expropriation or extreme levels of taxation. The oil price boom of the 2000’s was accompanied by seizures of foreign-owned oil investments in, for instance, Venezuela, Bolivia, Russia, and Kazakhstan.

This was by no means a new pattern. In the 1970s, the same phenomenon occurred: oil prices skyrocketed following the Arab oil embargo. Within a few years, nearly every major Western-owned oil and gas (and mining) investment in the emerging world had been seized – expropriated or nationalised – by host governments.

There is another lesson to learn from the 1970s resource-price surge. That is that eventually, resources prices will fall. And when they do, a new type of risk emerges. Regimes that have become dependent on oil revenues suddenly find they are desperately short of money. If these regimes have been relying on measures such as seizures of the assets of foreign investors to stay afloat, chances are their macroeconomic management is not very good.

The result is that when oil prices fall, the hitherto fast-rising incomes in these countries tend to crash (bad economic policy is procyclical), just when the fast-rising flow of resources available to the government to pay off supporters comes to a sudden stop. It is an illustration of that famous quote from Warren Buffet: “You never know who’s swimming naked until the tide goes out”.

The Iranian revolution of 1979 is perhaps the classic example. When the tide of oil revenues finally peaked, the regime of the Shah of Iran was exposed as wearing no pants. Incomes of the average Iranian suddenly stopped rising. Funds to pay the secret police were in short supply. Couple that with the Shah’s serious failings as a leader, and you have a recipe for trouble. That trouble came in the form of one of the original “people power” uprisings.

With China’s growth slowing, and industrial production in the US and Europe still weak, the oil and mineral price booms of the 2000’s appear to have peaked (thus far, perhaps the most dramatic softening has been the price of copper). As this softening extends to oil, Venezuela’s regime is uncomfortably exposed. Under former President Hugo Chavez Chavez, the country’s government had embarked on a programme of seizure of foreign (and domestic) investments so extreme that it came to resemble Cuban socialism. All well and good when record-high oil prices covered for economic incompetence. But now that oil prices have stopped rising, Chavez’s heir, Nicolás Maduro, is sitting uncomfortably in the hotseat, in a country ripe for unrest. If prices begin to fall, there could be real trouble.

It is not just Venezuela. Other oil-rich countries are also in uncomfortable positions. The timing of Iran’s charm offensive to attract international investment is no coincidence. The value of Nigeria’s currency has plummeted. And, as I argued recently, Russia’s situation is less secure than it appears.

For the leaders of oil-rich regimes this year, it is a good idea to have passports up-to-date and travel bags packed. Just in case.