Imagine World War II raging, and governments scrambling to cover the enormous costs, like heroes running a never-ending marathon with empty pockets. Enter the central banks, stepping in like coaches trying to keep their players on track. In the U.S.: The central bank promised to keep government bond interest rates low so borrowing wouldn’t become too expensive. This is basically what we now call Yield Curve Control (YCC), though back then, it didn’t have that name. After the war: Other countries tried similar strategies to manage their government debts. So, you could say YCC was like a hidden idea quietly at work during WWII, only becoming a formal, named policy decades later, especially in Japan in the 2010s.