What can only the national government do?

Answer 1

Art. I, Sec. 8 gives the Congress all its power to Legislate.

Tenth Amendment limits the powers of the Federal Government:

The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.

Art. I, Sec. 10 limits the powers of the States:

"No state shall enter into any treaty, alliance, or confederation; grant letters of marque and reprisal; coin money; emit bills of credit; make anything but gold and silver coin a tender in payment of debts; pass any bill of attainder, ex post facto law, or law impairing the obligation of contracts, or grant any title of nobility.

No state shall, without the consent of the Congress, lay any imposts or duties on imports or exports, except what may be absolutely necessary for executing it's inspection laws: and the net produce of all duties and imposts, laid by any state on imports or exports, shall be for the use of the treasury of the United States; and all such laws shall be subject to the revision and control of the Congress.

No state shall, without the consent of Congress, lay any duty of tonnage, keep troops, or ships of war in time of peace, enter into any agreement or compact with another state, or with a foreign power, or engage in war, unless actually invaded, or in such imminent danger as will not admit of delay."

Answer 2

Only the national government can wage war. They also have the exclusive power given to Congress to raise and support armies.

Answer 3

The federal government is the only one that can collect taxes. They are also the only ones that can make and maintain laws.

Answer 4

what the constitution designates as lawful

Answer 5

Declaration of War.

Signing of Treaties.

Answer 6

collect taxes