The Supreme Court shall have original and exclusive jurisdiction of all controversies between two or more States.
The Roman citizens gathering in assemblies to vote, is a fundamental element of a democratic society.
Answer: over twenty-five million
All of these are defensible. Of course debt rises in war, and decreasing taxes will benefit an economy where taxes are no longer needed (post-scarcity.) Political and geographical boundaries are outmoded and a world without them is not only possible but existed for much of early human civilization. As for the government, a government would run more efficiently when everyone is in basic agreement with what to do and how.
I would question your teacher on this. Anyone can defend these perspectives...
Establish and enforce laws