It well be a because that is the answer
True. Taxes are social responsibility of people to their country. Taxes are means of income sources for the government to operate. These taxes are used for building roads, repairs in cities, and healthcare programs. Without taxes, the government will not be able to provide its people the comfort and security they need.
This statement would be more or less correct I would say.
Nationalism inded did develop strongly in the 19th century, and also in a lot of cases led into the development of nation states. At the same time, powerful empires that existed in those times had often many different ethnic and political groups in their borders. All of these factors often led to different wars that were quite horrible.
One thing the Mesopotamia people had to adapt to was probably the regular river floods, they probably had to adapt their buildings, farms, and other structures to survive the flooding.