Relationship of international law and municipal law — Conduct of foreign relations — Power to declare war — United States Constitution granting Congress the power to declare war — Participation of United States forces in Vietnam conflict and other conflicts in South-east Asia — Whether President entitled to order participation without prior congressional declaration of war — Whether justiciable question — Political question doctrine

War and armed conflict — War — Definition — Participation by United States forces in Vietnam and other South-east Asian military conflicts — Whether participation constituting a war — The law of the United States