Okay kiddo, so there was this country called Iraq where there was a man named Saddam Hussein who was in charge. Some people thought that Saddam was a bad guy because he did mean things and broke the rules.
The United States and some other countries didn't like what Saddam was doing, so they decided to invade Iraq in 2003. This means that they sent a lot of soldiers and weapons to try and take over the country and stop Saddam from being in charge.
Some people thought this was a good thing because they wanted to stop Saddam from being mean and hurting people. Other people thought it was a bad thing because they didn't think it was the right thing to do or that it would cause more problems than it would solve.
There were also some disagreements about whether or not there were really good reasons for invading Iraq. Some people believed that the U.S. government was lying about why they wanted to invade, and that it was really about getting control of oil or gaining more power in the Middle East.
So, some people thought the invasion of Iraq was a good idea and would make things better, while others thought it was a bad idea and would make things worse. It's a complicated topic, and everyone has their own opinion.