Coining of money: FEDERAL GOVERNMENT
Fire and police protection: STATE GOVERNMENT
Schools: STATE GOVERNMENT
Army and Navy: FEDERAL GOVERNMENT
Treaties with other nations : FEDERAL GOVERNMENT
Highways and roads: STATE GOVERNMENT
Local courts: STATE GOVERNMENT
So, I'd say that Coining of Money, Army and Navy, Treaties with other Nations are most powerful.
This probably didn't help but I hope it did! :D
-LavenderVye
