lead, collaborate and negotiate with G-20+ to adopt a new World currency, initially partially backed by commodities.

USA lead the G-20+, and Collaborate and Negotiate a World currency partially backed by well-defined commodities. Such as 99.9% pure Gold, 99.9% Silver...Platinum, Palladium and Copper. And/Or a Barrel of Oil/Equivalent (5.8 × 106 BTU)... This World Wide Dollar (WWD) could be back 25% to begin with, and the percentage increased every year by 3%. So in 25 years the WWD would be 100% backed by well-defined commodities.
I propose the WWD trade freely with commodity prices and existing currencies. The Free market, i.e. arbitragers would keep all values relatively stable. Governments would have Balanced Budgets! Otherwise, their currency would be quickly be sold and WWD purchased.