Three Stages

In Parshas Shoftim we learn about the milchemet chova, a war to of defensive purposes.  In Ki Teitzey we move to the milchemet harishut, a war of aggression to conquer land.  The Torah launches into a discussion about a captured individual.  The following parsha, Ki Savo, opens with when Klal Yisroel is sitting tranquility in the land.  These are three stages in the development of the nation.  First the borders must be conquered and secured.  Then there is time for more conquest and finally the goal is to live peacefully.  These also represent three stages in a person.  The Or Hachayim comments that the parshiot of milchama also hint to one's battle against the yetzer harah.  First a person has to wage war against one's desires for forbidden things.  That is the milchemet chova to establish and secure one's borders.  After that is accomplished one can advance to the next level which is to extend one's kedusha beyond the basic borders of excluding issur but allowing one to bring kedusha even to that which is muttar.  To expand one's kedusha further.  That is the captive.  One captures that which was not even in their jurisdiction but rather that which was in the hands of the enemy.  After fighting one's battles one no longer needs to wage  war to conquer with kedusha for one has already conquered all they need to.  Any external kedusha will then automatically be attracted to the person.