Halakhah for Chullin 33:34

And also from this matter is that which they also said, that whether it is an optional war or a commanded, it is permitted for the front line of the army when they enter into the borders of the gentiles, and they are hungry and and they do not have provisions, to eat [their] foods - and even forbidden foods, such as carcasses, and 'torn' [animals] and pigs - and to drink idolatrous wine. And so did they, may their memory be blessed, expound (Chullin 17a), "'And houses filed with everything good' (Deuteronomy 6:11) - even [fatty] pigs' necks were permitted to us." And about this is it stated (Deuteronomy 20:10), "When you approach a city, etc." until the end of the section. [These] and the rest of the details of the commandment are in the second chapter of Sanhedrin and the eighth of Sotah.