Has the US ever been involved in a just war. Let's take a brief (and uninformed) review of history and the 7 points list (by the way the first one could be argued about endlessly.....were all means really taken beforehand).
Gulf War II(whatever its called): Point one failed, not all non-violent options exhausted before the use of force.
Afghanistan: Technically this may not be a war because of point 2, but looking at this points, this may be a just war?
Gulf War I: Point one failed....see Gulf War II above.
Vietnam: Failed point one and three.
Korea: (I don't know anything about this conflict and a skewed view presented by the TV Show MASH).
WWII: Failed because of point 7 (and 6?).
WWI: Failed at point 5 (and 6?).
Spanish-American War: (My lack of US military history fails me here, but this seems to be a war of expansion on the US part)
The American Civil War: Point one failed.
The War of 1812: ?????
The American Revolutionary War: Possibly fails because of point 2.
The bigger question is; have there ever been any just wars??