There's a scene in the film The Godfather Part III where Michael Corleone (played by Al Pacino) says: "Just when I thought I was out - they pull me back in."
And so it is with America and the Middle East, especially Iraq.
In this week's episode, Tim Marshall looks at the recent history of US military presence in the Middle East.
The number of American forces currently in Iraq is nowhere near the same level as in 2003. But the killing of Qassem Suleimani last week makes it unlikely US President Donald Trump will be able to bring US soldiers home from what he called "endless wars" in the region.