It was at least the case for the Vietnam War, where -- besides preventing the spread of communism, the "domino theory" -- there was no clear overall strategy or goals, so the objective and only metric of success was body count. In that war, the US goal was to kill the enemy.
Of course, the US has been widely criticized for using that strategy and it likely was a major factor in their failure to win that war.
It took me a short while to parse what you were saying because I never thought of enemy combatants as "the enemy". The actual enemy is the political force to continue fighting, which generally is very loosely correlated with the people on the front.
I guess that's part of the problem with the Vietnam War. The nominal enemy was the vague concept of communism, and the actual enemy were the (perceived hostile) people of Vietnam, so the goal became killing them, aka "body count". That was never going to end well, one way or the other.
Of course, the US has been widely criticized for using that strategy and it likely was a major factor in their failure to win that war.