Harder and more expensive, but far from impossible. I doubt they pay more than doubles Nvidia's sticker price, all told. Nvidia got into legal trouble recently for paying lip-service to sanctions - id you're keen on the mechanics of GPU sanctions-busting, read up on the governments accusations against Nvidia, and this was for low-hanging fruit.
The article has one analyst speculating they used tens of thousands of H100s (50,000 IIRC) instead of the 10,000 A100s the Deepseek CEO owns up to. They can afford to pay exorbitant markups for the logistical nightmare of importation through 3rd party countries at scale.
When I was working in Beijing, we definitely had resources we couldn’t access locally but could easily access remotely so it didn’t really matter.
https://www.tomshardware.com/tech-industry/artificial-intell...
If you follow the news, several people (bankers) will trade with Iran despite the repercussions (jail) of doing so. There is a premium but at the right price someone will execute.