It is very important to note that these frozen Iranian assets are US dollar-denominated. And what would be the first thing that the Iranians would do upon regaining control of them? Why, of course, they would convert them out of US dollars. This is a requirement written into Iranian law: no US dollars allowed, and nobody in Iran has the power to change that even if they wanted to. According to the Iranians, US officials have pleaded with the Iranians not to liquidate their dollar-denominated assets, but that the Iranians told them that nobody has the authority to change this law.
A sudden liquidation of this size would have punched an irreparable hole in the dollar system, which hinges on the ability to sell huge quantities of US treasury paper on the international market. The Iranian liquidation of dollar assets would have come at a time when the US is in dire need of foreign debt buyers, the demand is soft, and liquidity at the primary dealers for US debt is at record lows. It might have been enough to trigger a run on the US dollar as everybody dumped their treasury paper and lead to the collapse of the entire scheme by which the US robs the rest of the world by forcing it to continuously buy up its debt.
