"Alex is in Turkey."
First off, it would be "Türkiye'dedir." :)
You cannot really add the suffix to this anymore. It isn't a fact or strong assumption. The Hagia Sophia is and forever will be in Turkey. This is a fact and will forever be true. I, on the other hand, am not even in Turkey anymore and won't be for a while :) -DIr is used for encyclopedic facts, strong assumptions, and for a few other things. Look at this.