The Bush-Aznar Memo is a special letter written by two important leaders: George W. Bush (who was the President of the United States at the time) and Spanish Prime Minister Jose Maria Aznar.
Imagine if you and your best friend were writing a secret letter to each other to talk about something you didn't want anyone else to know. That's what the Bush-Aznar Memo was like, but instead of talking about a fun secret, they talked about a very serious topic - going to war with Iraq.
The memo was written in 2003 when there was a lot of talk about whether or not the United States and other countries should go to war with Iraq. The memo was supposed to be private and only between Bush and Aznar, but it got leaked to the press, which means a lot of people saw it and read what was in it.
The memo talked about how both men thought it was important for their countries to join together and go to war with Iraq. They also talked about how they believed that Saddam Hussein (who was the leader of Iraq at the time) had weapons of mass destruction, which are really dangerous weapons that could hurt a lot of people.
However, some people didn't agree with what was in the memo and thought that going to war was a bad idea. They thought there wasn't enough proof that Iraq had these dangerous weapons, and that going to war could make things worse instead of better.
The Bush-Aznar Memo is an important historical document because it gives us a glimpse into what world leaders were thinking and planning during a really intense time in history. It also reminds us that even important people have secrets and private conversations, just like you and your best friend might have.