The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened), against domestic Violence.
Art IV, Sec. 4, US Const.
Its solely the responsibility of the US Gov't to protect the homeland against invasion.
Sorry governor, your establishment of a state organized and supervised force to repel paratroopers is not authorized.