Okay, so imagine you and your friend got into an argument because they thought you had some toys that you weren't supposed to have. They want you to show them you don't have those toys, but you're saying you don't have them and don't need to prove anything. This argument keeps going back and forth and gets a lot of attention from other people who are trying to figure out what's going on.
Now, imagine this same thing happening on a much bigger scale between two countries, the United States and Iraq. The United States believed that Iraq was secretly making weapons that could hurt a lot of people and they wanted Iraq to prove that they weren't. Iraq said they didn't have these weapons and didn't need to prove anything.
This argument went on for a long time, and a lot of countries got involved to try and figure out what was going on. Some people thought the US was just trying to go to war with Iraq, while others thought it was important to make sure no one had dangerous weapons.
Eventually, after a lot of discussions and inspections, it was determined that Iraq didn't have the weapons that the US thought they did. But this whole situation caused a lot of tension and mistrust between the two countries, and it's still something that people talk about today.