You really need to pay attention to what is going on in the world.
It is one thing to not watch any shows and movies in years, but it is a whole different thing when you somehow missed out on events that affect everybody's lives in some way.
It is not that hard to read the newspaper, watching the nightly news on TV, or going to a news website on a regular basis.
The Iraq War and the War on Terror are two different things.
The Iraq War is part of the War on Terror, as stated in the Wikipedia article you linked to.
Was Day Z inspired by the War on Terror and/or the Iraq War?
Yes and no.
The game's premise has nothing to do with the War on Terror. It is about surviving a zombie apocalypse.
The game software itself, however, is a modified version of the military game ARMA 2, which is set in a modern war.
Why isn't the U.S. fighting ISIS and the Muslim Brotherhood?
They are. As you said but somehow forgot about, Trump did use drone strikes against them. You can read the Wikipedia article on ISIS to learn more.
I assume Rebel knows more about video games than I do. I am wondering why he's not responding.
Because you responded late at night when most people are sleeping.