He believed it was essential for the Union that states maintain strong, autonomous state governments. If the states were enfeebled, then discord would grow between them even more and people would not be fond of the federation as they would feel it was foisting unjust laws on them. I hope this helps, and my apologies if it somehow is incorrect.
This statement is false. Sumerians did not trade because they were curious about other cultures, but because they needed to acquire more resources from neighbouring countries in order to survive.