Look at the map showing the european union (eu) and countries with which it has free-trade agreements (ftas) which is the reason the eu has free-trade agreements with almost every country on the mediterranean sea?
having a sea border between an fta country and the eu is more secure than a land border

having a shoreline makes shipment by sea possible, which is less expensive than over land

the countries in north africa and the middle east are potential members of the european union

the countries in north africa and the middle east are less politically volatile than other countries