I think the house should simply de-fund DHS until such time as they get answers to legitimate questions. The house can also cancel these silly 2 Billion rounds of ammo contracts.
As for the unlikely senerio of china or Russia holding gold and demanding payment, it would be a choice of paying them and the US going bankrupt or just showing them our middle finger and saying, "We're not paying you! Suck it!"
They would make us go it alone, but in reality; the US has gone it alone for 60 years.
They would have 2 choices, bend over and take it in their you-know-what stained shorts, or start a war to try & collect. They will just grumble and take the hit. Yeah, we would be on a cash & carry basis, but that may be a good thing.