Spending those $US reserves

Nations will realise that spending those $US dollar reserves by buying USA goods and services will bring about stability in the world. Free trade = multilateral trade not one way trade. You have to take care of your customers. If you want Americans to buy more of your goods, you need to buy their goods too. The other way is for Nations to distribute these $US dollar reserves to its citizen for travel to USA and spend their money there. 

Spend those $US reserves buying USA goods and services, it is common sense.

A USA dollar collapse is not going to help any nations with huge US$ reserves.