Sense of patriotism.

When the Torah speaks about the message the priest called mashuach milchama (anointed for war) speaks to the people in order to get them ready for war, there are a few things that the Mishna requires the priest to say which need explanation. The Mishna(סוטה מב, א)  which deals with going to fight wars opens with a strange requirement. It emphasizes that the priest must speak to the soldiers only in lashon hakodesh, the holy language, and not in any other language. The obvious question is why, what's the difference what language he uses to convey Hashem's message to the nation before the battle?

The Mishna continues, saying that he opens up to speak to them by saying "Shema Israel" - "Listen, Israel." The Gemara explains that the reason is to remind them of the declaration of Shema Israel, which sanctifies Hashem's name and is the symbol of what every Jew is required to say every day and night. But why is it important before going to war to say that?

The Mishna then further elaborates with the words of the priest, emphasizing that in going to battle, we are fighting as the pasuk says: "Against your enemies" and not against your brothers. This is not a war between the tribe of Yehudah and Shimon, nor Shimon against Binyamin. If, unfortunately, you fall into the hands of your enemies, they will not show mercy, unlike the compassionate treatment described in a war between Yehudah and Israel: "And the men that have been mentioned by name rose up, and took the captives, and with the spoil clothed all that were naked among them, and arrayed them, and shod them, and gave them to eat and to drink, and anointed them, and carried all the feeble of them upon donkeys, and brought them to Yericho, the city of palm trees, unto their brethren; then they returned to Samaria" (ד״ה ב, כח).

Here, the Torah teaches us the secret to success in war: the main goal is to make people feel connected to their roots and nation. When one goes to fight for their nation, they must feel the strong sense of patriotism. This is precisely what the Torah instructs the priest to convey to the soldiers.

It's enlightening to see how in the recent war so many non-religious Jews suddenly became very interested in connecting, whether by wearing a tallit katan or tefillin.

There is no doubt that the connection to one's roots plays a big role.