Military Tribunals or Federal Court

Act of War I am having trouble getting a good grip on this question: Who should have jurisdiction over perpetrators of violence against the United States, a Military Tribunal or a Federal Court? Perhaps a corollary question might be, what is an "Act of war?" I have no problem with a military tribunal having jurisdiction over the perpetrator of violence against the United States when the violence is an act of war. The crux then becomes, what is an "act of war?" And, must the U.S. actually declare war against the perpetrator(s) in order to try the perpetrator(s) in a military tribunal? So, if that be true, then if the violence is not determined to be an act of war it must just be a criminal act and hence be tried in a Federal Court. Now, if only Congress can pass a Declaration of War, does it also follow that it must be Congress who decides if the violence is or is not an "act of war?" In that, I believe so. So, just what constitutes an act of war? Was the bombing of the Murrah building (Oklahoma City) by an American citizen an act of war? I'd think not. It was an individual committing a criminal act--wasn't it? Was there ever any conjecture over it not being a criminal act? Don't think so. And of course McVeigh was tried in a Federal Court. But, was flying airplanes into the Twin Towers in New York City, also by individuals, albeit not U.S. citizens, but individuals who were citizens(?) of a foreign country (They were Arabs but did not attack the U.S. under auspices of Saudi Arabia), a criminal act or an act of war? Now, they were associated with a cohesive group, a named entity not specifically identified with or representing any country. Can an individual(s) not acting under the auspices of an autonomous, sovereign country commit a bonafide "act of war" against a sovereign nation? Now, the bombing of Pearl Harbor most certainly was an act of war, Congress said so--it was a heinous act by one nation against another--and it led to a Declaration of War. So, say this, was 9/11 an act of war or just another criminal act; a heinous act of terror either way? Hmmm, did the U.S. declare "war" on Al Qaeda? Or just terrorists, or terrorism? Can you actually declare war on an individual or a group of individuals? Just how would you be able to tell a terrorist (or a "terrorism"?) from someone else? How can you tell the difference between one who is "in" Al Qaeda from some nondescript muslim (Arab) bricklayer? Or can we, as a nation, just dance along the yellow brick road making decisions this way, that way, as we feel the wont at any time? I think we should first qualify an act of violence as the first order of business. Is it an act of war or is it a criminal act? Let Congress pass judgement and the rest is easy. You then define, deleniate the parameters of the enemy and then go get him, it. Comments would be appreciated.