1. Nothing in this Constitution shall be implied to preclude or prohibit any member of the armed forces or law enforcement officers of the United States or of any of the states or other jurisdictions from employing whatever armed force may be reasonable and necessary to protect the United States, the people and their property from threatened harm through the commitment of a felony or an act of war in progress. Said actions shall not be deemed to have violated any person's due process rights, provided that said person was actually engaged in an armed or violent threat against people or property.
2. This amendment does not establish an authority for the President or any subordinate to the President, or for any State or other jurisdiction, to employ deadly force in the "pre-emption" of any person believed to be intending but not yet actively engaged in the perpetration of an armed or violent threat against people or property. Such pre-emptive actions are only hereby authorized upon the issuance of warrant by a court of law with applicable jurisdiction after due process in the case of individual persons, or upon the declaration of war by Congress upon a nation or non-state entity.
(This attempts to strike a balance. We need our people in uniform, and those in charge of them, to have the authority to do what they have to do to actually protect people that are immediately threatened by violence, without having their hands tied by legalities. On the other hand, we don't want this to just open the door wide to any and every kind of abuse. If the threat is not real and in process, then pre-emptive strikes cannot be undertaken without prior review and authorization by non-executive authorities.)