The Question of a Just War: Is there such a thing as a just war?
 
This is a question that goes way back to the earliest times of ethical considerations of the concept of war. To claim a moral justification for any war, certain conditions are required. Some of these conditions are: the war must be in self-defense or/and defense of others unjustly wronged; it must be the last resort taken on after all other alternatives for a peaceful resolution are exhausted; it must be with a good intention, for instance, to correct a grave and public evil perpetrated against the very basic rights of whole populations; the actual execution of such wars must be humane --- the force used must be proportionate to that used by the aggressor, that mercy be shown when the aggressor surrenders, etc.; it must carefully guard against hurting any innocent civilians in any way; and must be fought by a legitimate authority.
 
Although such guideline requirements are provided, when it comes to the actual cases, it is difficult to figure these out. For more details on these, consult these websites:
 
http://www.pugwash.org/reports/rc/beach.htm
 
http://www.npr.org/programs/morning/features/2002/jan/justwar/020125.justwar.html  
http://www.nationalreview.com/interrogatory/interrogatory101501b.shtml
http://www.zetetics.com/mac/articles/justwar.html
http://www.usccb.org/comm/nationaltragedy/justwar.shtml#justwar
http://www.mtholyoke.edu/acad/intrel/pol116/justwar.htm