Okay, imagine you have a special notebook where you keep track of all your money, kind of like a diary. Now, let's say you want to make friends with someone, but you don't know how. You could just talk to them, but sometimes that doesn't work, right?
Well, some people use something called "checkbook diplomacy" to make friends. This means they use their money to help other countries, and then those countries might be more friendly to them in return.
Just like in your special notebook, these people write a check (a piece of paper that says they will give a certain amount of money) to the country they want to help. That country can use that money to build things like schools, hospitals, or roads.
By helping out, the person who wrote the check is hoping that the country will like them more and maybe be more willing to work with them on other things. It's kind of like making a new friend by giving them a present.
But some people don't like checkbook diplomacy because they think it's not fair. They worry that the person who wrote the check will have too much power and control over the country that received the money. So, it's a complicated topic, but that's the basics of what checkbook diplomacy is.