It's just that Saddam was hung in a fully occupied country.
And the occupiers are fully responsible for law and order in an occupied country.
And so a reasonable person might conclude that the occupiers hanged Saddam.
Saddam made the terrible mistake of trying to sell his oil in Euros rather than USA Dollars, the Reserve Currency of the World.
If Saddam had succeeded in selling his oil in Euros, Saudi Arabia may have followed suit, and then the rest of the oil producing world.
This would have led to a change in the Reserve Currency of the World. And the USA would now be exposed to bankruptcy.
Saddam was a clear and present danger, not only to the USA, but to the world's financial system.
So we hanged him.