You’re question makes no sense.
Upon encountering a statement you do not understand, the prudent thing to do is to nod sagely and continue in silence.
Publishing the fact that you are confused does not serve you well.
However, to attempt to explain briefly: Any military man, having given an oath of fealty or obeisance, and even before, has a duty to himself to consider all the ramifications and possibilities his oath may require of him. Oaths of meaning should not be given lightly.
Defending against foreign enemies is an easy task to analyze; even the most raw recruit can be told to run toward the sound of the guns.
Discerning who is the enemy is not so straightforward. The enemy who can do the most damage is the one who infiltrates your ranks. Ferreting out that enemy requires patience and cunning, not mere servitude.