Take a look at the U.S. and decide for yourself.  Would the U.S. be as successful if it were a collection of 50 independant states, each responsible for its own treaties, currency, and armed forces?  The redundancy and inability to coordinate and consolidate efforts would likely render the whole as ineffective.\n\nThere should be, however, reasonable limitations on the powers of the chief executive of the federation.  The U.S. bestows tremendous powers on its President.