I think that is exactly what it is.
I have no doubt they would if they could. But I'm trying to wrap my head around the idea of how they would do it without outright rebellion
Most 401 (k) are employer run and I can't see the US government mandating them to transfer the value of the stocks, bonds to the treasury
I could see them asking companies to let the government borrow against the value, but again it would be political suicide