1) The president is not empowered to order a military attack against any nation. According to Article One, Section Eight of the constitution.
2) Miranda warning. The U.S public policy allows for such a practice. If the current U.S. policy is to allow such a practice, it would be lawful since almost all the governments all over the globe have embraced Miranda like rights and thus is applicable at any time.
3) The fighters will get access the U.S. federal Court System since it acts as the guardians of the Constitution, therefore, it should fairly and impartially interpret and apply the law.
4) A military tribunal is a kind of military court, which is designed, to try members of enemy forces during wartime. The United States uses military tribunals rather than relying on a court-martial, within the military justice system, during times of declared war and rebellion.
5) Yes. The US military has developed software that can let it manipulate social media sites, such as facebook, secretly by using fake online personas to influence internet conversations. Governmental agencies involved include the NSA and CIA global spying network. It is not lawful for the government to participate in such activities.
6) A constitution consists of a set of rules creating and structuring. It also defines the limits of government authority or power. The constitution has some fundamental bills of rights. There is power sharing between the national, and state governments.
7) No. Attacking another country without provocation is against the law.
8) The Legislative Branch holds all the cards in this discussion. They write laws, levy taxes, declare wars, confirm the Supreme Court Justices and Cabinet Officials and decide on how the federal money is spent, amongst other actionable powers.