Sorry, it’s politicized - claims that the US is ZERO RISK when they’re already involved with stealing a HUGE amount of money.
The risk premium is a “revealed preference” metric, the implied risk international investors allow. You will have to argue this with vast numbers of people and institutions.
It’s also relative. It’s not zero risk absolutely, but compared to the available options. If you were the Kuwaiti national oil company and you had to park some money for a while, would you buy US bonds or Chinese? How much greater yield will the Chinese have to give you to try them out?