§ 466. “Protect every State against Invasion.”
The Commonwealth is required to protect every State against invasion. The courts have interpreted the phrase, “United States” in a similar section in the American Constitution, to mean the Federal Government. (Luther v. Borden, 7 How. 1. See Pomeroy, Const. Law, § 101.) Hence the injunction that “the Commonwealth” shall protect a State refers to the Federal Government and not the political community of which that Government is an organ. The power and duty to protect against invasion may be exercised by the Federal authority on its own motion and according to its own judgment and discretion, without the necessity of an application from any State organization within the State.