Originally Posted by Neezar
Question: Can a president of the United States declare and engage in war?
Yes, it is possible for a President of The United States to declaire and Engage in War in two ways
There are Two Barriers he must overcome. The First is it must be Legal within his own Law. This mean he must get approval from his Government first. Then he needs Approval from the International Community by way of a Sanctioning United Nations Vote. The reason for this is simple. A country has no jurisdiction outside of its Soverignty. The Country you war with is not US soil, therefore you need a world opinion on the matter before you tread on anothers soil.
Once both are obtained, the President may do what he wishes outside of his Jurisdiction in regards to the Nation against which he is fighting. He shall also be entitled to complimentary Troops from other Organisations of an International Standing, Probably members of the Security Council, Possibly a Force by the North Atlantic Treaty Organisation, or a selection of Troops forming a United Nations envoy of some type.
If The United States is attacked by another Force whether provoked or not, it has an immediate right to respond should it wish to. The result may be warfare. This action does not need the specific approval of the International Community, and is taken as a given that the Government would support the President in such an activity.
These Guidelines are not applicable to a case of Civil War.
These Guidelines do not sanction genocide or war crimes
These Guidelines are subject to Human Rights of the Enemy during warfare as specified under The Geneva Convention (please note not all Countries abide by this in every respect at war, and I personally dont vouch for everything specified, for example, I am pro-use of Torture under interogation which is strictly forbidden)
Hope that helps