S: (n) desertion, abandonment, defection (withdrawing support or help despite allegiance or responsibility) "his abandonment of his wife and children left them penniless"
S: (n) pullback ((military) the act of pulling back (especially an orderly withdrawal of troops)) "the pullback is expected to be over 25,000 troops"
S: (n) retreat ((military) withdrawal of troops to a more favorable position to escape the enemy's superior forces or after a defeat) "the disorderly retreat of French troops"
S: (n) receding, recession (the act of becoming more distant)