John Maynard Keynes first proposed the ICU

John Maynard Keynes first proposed the ICU (International Clearing Union) in 1941, as a way to regulate the balance of trade. His concern was that countries with a trade deficit would be unable to climb out of it, paying ever more interest to service their ever-greater debt, and therefore stifling global growth. The ICU would effectively be a bank with its own currency (the "bancor"), exchangeable with national currencies at a fixed rate. It would be the unit for accounting between nations, so their trade deficits or surpluses could be measured by it.