U.S. Constitution, Article I — The Legislative Branch, Section 10, Clause 3
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.
Notes
Bars states, without the consent of Congress, from laying any tonnage duty, keeping troops or ships of war in peacetime, entering agreements or compacts with another state or foreign power, or engaging in war. Exempts a state that is actually invaded or in imminent danger admitting of no delay.
Use as reference
Lexinter.net | U.S. Const. art. I, § 10, cl. 3 | https://laws.lexinter.net/constitution/us/article-1/section-10/clause-3