The Petrodollar: how oil keeps the dollar on top

A textile factory in Vietnam, a power plant in Germany, an airline in Kenya. None of them does much direct business with the United States, and all of them need US dollars before they can run, because the oil they burn is priced and paid for in dollars. Multiply that across every country that imports energy and you get a quiet, permanent demand for the American currency that has nothing to do with America's own trade. That demand has a name. People call it the petrodollar, and for fifty years it has been one of the load-bearing walls under US power.

What the petrodollar actually is

Start by clearing up the word, because it sounds more exotic than it is. A petrodollar isn't a special currency. It's an ordinary US dollar that happens to have been earned by selling oil. When Saudi Aramco ships a tanker of crude and gets paid in dollars, those are petrodollars. That's the whole vocabulary.

The system is what those dollars do next. Oil is priced and settled in dollars almost everywhere, so any country that needs to import it, which is nearly all of them, has to acquire dollars first and keep a reserve of them at its central bank, ready to pay. The exporters, meanwhile, end up with far more dollars than they can spend at home, so they park the surplus in the safest dollar assets going, mostly US Treasury bonds. The money makes a loop. Importers buy dollars to buy oil, exporters earn those dollars, exporters lend them back to the US government and US markets, and round it goes. Henry Kissinger's circle had a phrase for the back half of it: petrodollar recycling.

The loop itself isn't the point. What matters is what it produces, a steady structural appetite for dollars from countries that otherwise have no special reason to want them. That demand is the engine. Everything else the petrodollar does for the United States runs off it.

The deal in Jeddah

The setup didn't appear by accident, and the year that matters is 1974. To see why, rewind three years. In 1971 Nixon ended the dollar's convertibility into gold, cutting the last hard tie between the dollar and any commodity and leaving it to float on trust alone. Then in 1973 the Yom Kippur War broke out, the US armed Israel, and the Arab members of OPEC answered with an embargo. Oil roughly quadrupled in price. Western economies got hammered with shortages and inflation, and a wall of money suddenly came rushing into a handful of Gulf capitals.

It helps to see the whole arc on one line before the detail.

In the summer of 1974, US Treasury Secretary William Simon flew to Jeddah, officially on a goodwill tour, in fact to make a deal with the Saudis. The arrangement that came out of those meetings ran on a simple trade. Saudi Arabia would keep selling its oil for dollars and steer its growing surplus into US Treasuries, and in return the United States would sell it advanced weapons and stand behind the kingdom's security. Within a year or so the rest of OPEC fell in behind dollar pricing, following the largest producer.

It's worth being precise about what was and wasn't signed, because the popular telling oversells it. There was no secret treaty that forced the world to price oil in dollars. Oil was already quoted in dollars before 1974, simply because the dollar was the most used and most liquid international currency, and the formal US-Saudi agreements of that year were mostly about military and economic cooperation rather than a binding currency clause. What Jeddah really locked in was the recycling, the security relationship, and the Saudi decision to peg the riyal to the dollar. That's less cinematic than a hidden pact, and also more durable, because it rested on mutual interest rather than a piece of paper either side could tear up.

Why Washington loves it

Here's where the petrodollar stops being trivia and becomes power.

Because the whole world needs dollars to buy oil and keeps a stockpile on hand to do it, there's constant demand for the currency and for the safest place to hold it, US government debt. That demand lets the US borrow more cheaply than almost anyone, since there's always a deep pool of buyers for Treasuries. Economists gave this a slightly envious name decades ago, the exorbitant privilege. The country at the center of the system gets to run large deficits and pay less to finance them than a country without a reserve currency ever could.

The second advantage has a harder edge. Because so many international payments are denominated in dollars and clear through American banks or the correspondent network wired into them, the US can reach into transactions that happen nowhere near its own soil. That's the machinery behind sanctions. When Washington cuts a country or a bank out of the dollar system, it isn't seizing anything physical. It's denying access to the plumbing that most of global trade flows through, and that has turned out to be one of the most effective instruments of foreign policy of the last half century. The petrodollar didn't invent the dollar's centrality, but it has kept reinforcing it.

Here's how thoroughly the dollar still sits at the middle of things, by the metric that matters most to you.

The cracks, and the noise about cracks

So is it ending? You'll meet that claim constantly, and the honest answer is yes, slowly and partly, and nothing like the collapse the headlines keep promising.

Start with the genuine movement. Russia, locked out of the dollar system by sanctions after invading Ukraine, now settles much of its oil trade with China in yuan and rubles and has run down its Treasury holdings. China has stood up yuan-priced oil futures in Shanghai and leans on its trading partners to settle in yuan where it can. Iran has reportedly collected some tolls in yuan. The BRICS group keeps floating plans to cut its dependence on the dollar. And the dollar's share of global central-bank reserves has drifted down from around 72% in 2001 to roughly 57% today, as reserve managers spread into a wider mix of currencies.

Now the reasons it isn't unraveling. That same 57% is still more than the euro, yen, pound and yuan combined, and the decline has been steady diversification into smaller currencies like the Australian and Canadian dollar rather than a flight from the dollar. Around 80% of oil is still priced in dollars. The yuan, the challenger everyone names, is boxed in by China's capital controls and managed exchange rate, which is exactly what makes central banks reluctant to hold much of it. Switching the currency of a major oil contract means rebuilding the contracts, the hedging, the insurance and the pricing around it, while the dollar's depth lets you move billions without moving the market. Even the United States becoming the world's biggest oil producer after the shale boom, so that it now buys far less Saudi crude than China or India do, hasn't shaken the pricing convention loose.

What you're left with is a slow, selective drift, not a turning point. Countries peel away from the dollar where politics forces them to, mostly under sanctions, and keep using it everywhere it stays the convenient choice, which is almost everywhere. The petrodollar's grip is loosening at the edges. The center is holding, and it will keep holding until something matches the dollar's depth and openness, which nothing yet does.

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Further reading: the Federal Reserve's 2025 note on the international role of the dollar, the IMF's COFER reserve data, and NPR's history of the petrodollar regime.