Because you can generally get what you want from some arrangement that falls short of complete merger. If you want economic strength without military union, you can join NAFTA, if you want military union without economic union you can join NATO. Even “mergers” usually leave their constituents as federated States with some control over their own affairs.
Because you can generally get what you want from some arrangement that falls short of complete merger. If you want economic strength without military union, you can join NAFTA, if you want military union without economic union you can join NATO. Even “mergers” usually leave their constituents as federated States with some control over their own affairs.