War is horrible. It takes innocent lives, causes great suffering and causes many of the people involved in the actual fighting irreversable psychological damage.
War is above all immoral.
But, war is necessary. No one likes to think that our only way of solving conflict is by violence but it is a sad fact of our lives. It would be nice to be able to sit down and talk things over but some people are irrational. They are willing to do anything to win. In these cases we cannot sit idly by while we and others are trampled by tyrants.