Whenever any portion of the militia of the State shall be on duty under or pursuant to orders of the Governor or whenever any part of the militia shall be ordered to assemble for State duty, the systems and procedures established in the Uniform Code of Military Justice for the governing of military forces, so far as applicable and not in conflict with any rule or regulation herein prescribed, shall be considered in full force and regarded as a part of this chapter until such forces shall be duly relieved from such duty, except that nothing in this section shall be construed as relinquishing the State's authority and jurisdiction in such matters. No punishment under this section extending to the taking of life shall in any case be inflicted except in time of actual war, invasion or insurrection declared to exist by proclamation of the President of the United States or the Governor of this State, and then only after the approval of such sentence by the Governor. The Governor shall review the findings of all general courts-martial convened during such situations hereinabove recited.