War is always regarded as a sin (Aquinas  Summa  Theologiae  Extracts  II-II
            
 q.40 a.l). The great medieval thinker, Saint  Thomas  Aquinas,  demonstrated
            
 and developed his ethical theory  and  limitations  of  waging  war.  It  is
            
 unlawful to trigger warfare in any situation, in  terms  of  the  belief  on
            
 Christianity. However, Aquinas objected to the theory, and claimed that  war
            
 can be considered as  a  just  war,  under  the  certain  circumstances  for
            
 warring that are built upon  three  restrictions.  Aquinas  indicated  these
            
 factors could promote war  into  the  attribution  of  Just  by  giving  the
            
 authority  of  the  prince,  judging  the  validity  of  doing  things,  and
            
 righteous intent (Aquinas Summa Theologiae Extracts II-II q.40  a.l).  Based
            
 on these aspects, war is  not  evil  as  most  people  thought,  because  it
            
 concerns more about morality and  virtue.  In  addition,  Aquinas  suggested
            
 that just also embodied the aspect of murder, such  as  innocent  sacrifice,
            
 and killing on self-defense in the certain occasions.  Personally  speaking,
            
 those limitations should not be applied to the  modern  warfare.  There  are
            
 many fallacies can be taken for preposterous  reasons  of  waging  the  war.
            
 This essay will indicate the  examples  that  happened  in  recent  military
            
 history, and explain why  those  limitations  can  not  be  used  in  modern
            
  There are two restrictions of waging war,  that  is,  private  command,  and
            
 intention. According to Christianity (Aquinas Summa Theologiae Extracts  II-
            
 II q.40 a.l), the sin is always  influencing  the  quality  of  virtue,  and
            
 obviously, war is opposed to peace. Moreover, all kinds of  military  drills
            
 are lawful and come up with the directly reasons  of  its  own,  except  the
            
 marital contests for massacre (Aquinas Summa Theologiae Extracts II-II  q.40
            
 a.l). What if the purpose of doing military  practice  just  for  "perso...