Found this in a article of the Jewish Post, Indianapolis, Marion Country, 15 January 1992 in a Sidrah of Beshelach from the hand of Rabbi Reuven P. Bulka.
To be a master of war means to master war, but to be a master of war is more than just being a superb general, an ingenious tactician, or a brilliant strategist. It means to be a winner in war AMD a winner in life. It implies the capacity to wage war even while loving life - to protect without militaristic experience has a contagious effect in which it is quite easy to become insensitive to life.
Only G-d can be called a Master of war because all those who take part in battle are G-d’s own children, and remain as such. Battles are never pleasant. G-d is the Master of war. G-d is His name. The essence of G-d does not change through militarism. In life, there is an obligation to emulate G-d. It is impossible to be as G-d, but it is possible to emulate, to be aware of, what is godly, and to approximate, this godliness to whatever human extent possible. In the dimension of war, this implies the obligation not to let the necessity to fight in-vade the personality.
Yaakov, when he was about to confront his brother, Esav, was greatly
afraid and distressed (Bereshit 32:8). The midrash explains this
double anxiety state as referring to two things which worried Yaakov -
the fact that he might be killed, and the fact that he might kill
others. Why was Yaakov botheted about having to kill others? Perhaps
because he did not know what effect this would have on his
personality, whether it would change him from a peace-loving
individual into a bellicose, belligerent individual. This disturbed
Throughout Jewish history, we have had many military confrontations, but we do bot gloat over them. Indeed, the very victory over Egypt is only a partial celebration for which a half of Hallel is recited on the last six days of Pesach (Arachin 10a). The first days celebrate the leaving from Egypt, which was a total celebration. The last days celebration, the annihilation of Egypt, can never be a total celebration. Hannukah is celebrated not on the day of victory but on the day after, the day of rededication of the Temple. The holiday of Purim was made possible by military victory, but Purim is celebrated on the day the Jewish people ‘rested from their enemies’ (Esther 9:17-18).
These are subtle but potent emulations of the godly quality that war should not permeate and overcome one’s human tendencies. In our time, this very feature is lived in the delicacy of Israel’s existence. Almost every able-bodied citizen is at once a defender of the state and a lover of peace. The Jewish subconscious relates back to its primordial roots.