It strikes me that the Spanish government's current tactic of delaying crossings at the frontier of Spain and Gibraltar is illogical. If they maintain that Gibraltar is part of Spain, they should remove all frontier controls.
People who often question the role of the EU in maintaining peace in Europe are missing the point. The dispute over Gibraltar is a small example. Traditionally such disputes were resolved by force of arms. Today the argument is referred to the European Commission and the European Court of Justice.
