I’ll try the “like I’m five” variant. I’m not great at it, and making it five-year-old-friendly means saying some things that aren’t strictly true for simplicity, so go easy on me:

You know how you have coins? That are made of real metal? It used to be that we used metal as money, because metal has uses — if you have some gold, you can make a ring, or some foil to protect a spaceship.

But there just isn’t as much gold or silver as you would need to represent all the things in the world. You need enough money to be able to trade everything, including the gold and silver themselves, and there’s only so much gold and silver in the ground.

So we made a new idea. Money would be based on debt. When you spend a dollar, that dollar is backed by debt that our government holds — you have a piece of paper that says you have a little tiny piece of the US debt that you own, and you can trade it.

But that debt is only as valuable as the person who owes it. If the government decides it doesn’t want to pay its debts, the paper you have is worthless. Treasury bills are a special kind of money, where you can loan the government money and they give you more back at the end. It’s like if you give me $5, and I promise you I’ll pay you back $6 next week. You can trade it to your friend for a baseball card, and they can bring me our contract and I’ll give them the $6 instead.

The more of these Treasury Bills people buy, the more money we have. When you give me the $5, I can buy us some chicken nuggets today, even though my payday isn’t until Friday. But if people stop buying my bills, I have trouble! The less people buy them, the less they are worth, and the less they are worth, the more I have to sell to cover my debts. And that is what we use a lot of our treasury income for — rolling forward existing loans. Say I owe you $12 from our earlier deal, where I borrowed $5 but pay back $6. I only have $7, so I can pay off one bill for $6, but for the other $6, I’d like to sell you another $5 bill and then pay you back with your own money. But if you don’t want to buy my bill, I won’t have money to pay you back.

And that’s what’s scary for people — if there isn’t enough new money coming in to pay the old debts, what will we do?