So here's the thing about being the world's factory: you need a lot of energy to keep the lights on. And for China, the bill for that energy just got a lot more complicated.

Mohamed A. El-Erian, the chief economic adviser at Allianz (ALIZF) (which owns the giant bond investor PIMCO), pointed out this week that China is getting squeezed from two sides on the energy front. It's not just about paying more; it's about losing access to the cheap stuff altogether.

First, there was Venezuela. For years, China had a sweetheart deal for discounted oil from the South American nation. That's now effectively gone, thanks to U.S. intervention. The U.S. has pulled Venezuela into its sphere of influence, which means China can't really develop the infrastructure there anymore. Oh, and the kicker? The revenue from Venezuelan oil sales is now flowing directly into a U.S. Treasury account. So much for that discount.

President Donald Trump did say China was welcome to make a "great deal" on Venezuelan oil, noting that India was already in talks. But that's a bit like your neighbor cutting off your water line and then offering to sell you bottles from his fridge. The terms have fundamentally changed.

Now, the second shoe is dropping. El-Erian notes that China is running into trouble with its other major source of cost-effective energy: Iran. This isn't just about Iran itself; it's about everything that flows past it.

Last year, Saudi Arabia, Iraq, and the United Arab Emirates exported more than 13 million barrels of crude per day through the Strait of Hormuz. A huge chunk of that was headed for China. With Iran now closing that strait, all those shipments are suddenly at risk. That's not a supply hiccup; that's a potential heart attack for China's energy imports.

When asked by Reuters about whether U.S. actions in Venezuela and Iran could choke off oil supplies, Chinese Foreign Ministry spokeswoman Mao Ning gave the kind of answer you'd expect: Beijing "will do what is necessary to safeguard its energy security." It's a firm statement, but it doesn't magically reopen shipping lanes or restore discounted contracts.

All of this is happening at a particularly bad time for China's economic playbook. El-Erian points out that China's 2025 strategy is to drive growth by expanding its global exports, trying to make up for shipments that aren't going to the U.S. anymore. But if your energy costs are going up and your supply routes are getting blocked, that whole "export our way to growth" plan starts to look, as El-Erian put it, "increasingly difficult to repeat."

It's a classic double bind. You need cheap energy to make cheap goods to sell to the world. But if you can't get the cheap energy, the math on the whole operation starts to fall apart. China is now staring down that exact equation, and the variables are not looking friendly.