Hi I have a question regarding country fixed effects. I am quite new to this subject, so apologies for the silly question!

I have a model that try to consider what determines the adoption of a specific technology, my independent variables are fdi and some local variables (Patents, export, DVA, etc). I have 34 countries for 12 years. I am running OLS and IV. with time fixed effects. Is it really necessary to have country fixed effects if I control for GDP or population and regional areas? I divided my countries in economic and geographic regions and I am running my models with these three dummies. Is it ok or do I have to insert country fixed effect? Thanks