extra credit ( what is the function of war?)

war can be divided into two situation
one is that war can be good. and other one is that can be not good
first
war can give winner country many things good. so the winner country can advance easilly because the winner country may have many resources so the country will be more stronger and influential.
 however
war can be degeneration, because failled country lose anything. for example: money,  many resources etc. so the failed country can be poor and weak. and war causes social muss.