The country that will be fearing our exit is Germany. Europe's common enemy has reached a stage where there is nobody to help them out of the mess they created.
Their greatest fear is our exit will prompt the states to leave, and leave them "holding the baby" for once. Germany will not have seen such destitution since the end of WW2 - I wouldn't be surprised if there is a rise in support for the left-wing movement.
Economists foretell Germany won't get back on its feet for over 1,000 years - thank the Lord for Brexit - they could have taken us with them.