And you will note that there has been no moves around the world to merge other airlines
Successful mergers are about synergies. The whole being greater than the sum of the parts. Air France/KLM has had mixed success and in some ways turned into a reverse take-over. Lufthansa just went on a spending spree, unfortunately it didn't have the money and it's purchases didn't have the passengers. Looking over the pond there has been a long track record of airline consolidation but no healthy super-airlines have emerged.
My points are that BA and Iberia don't have a great deal of synergies.
Mergers and takeovers without obvious synergies are just land grabs. Land grabs flatter egos. Unfortunately they come down to earth with a bump 3-4 years later when the magic has blown away. Larger companies just have larger problems. If they're really lucky they can always divorce, for example Daimler-Chrysler a company for which synergies are tangible to all but were impossible to implement.
There's only one successful synergy I can think of. If a pig farmer, chicken farmer, baker and sauce maker were to merge I would definitely taste the benefit!
