No state shall enter into any treaty, alliance or confederation.
No state shall without the consent of the congress lay any imports or duties on imports/exports.
States may not enter into a treaty with a foreign nation; that power is given to the president, with the advice and consent of two-thirds of the Senate present.
No State shall, without the Consent of Congress, lay any Duty of Tonnage, keep Troops, or Ships of War in time of Peace.