The IDF Rabbinate has related to this situation with instruction how soldiers deep in Gaza can continue keeping kosher in this mess.

To start it should be mentioned that generally, almost always, the IDF is supplying food to soldiers in Gaza no matter where they might be so in general soldiers should not be going hungry. The following guide was written for soldiers in Gaza in general and not for situations where soldiers might not have been and are famished without any food available (to be read the English way, not the Yiddish way).

Fresh fruits and vegetables found in Gaza can be eaten. As well, eggs, salt, coffee, green or black tea, sugar, legumes or flour, squeezed juices, noodles, oil, spices like paprika, pepper, cinnamon, turmeric and some others can be consumed even if they are found with no hechsher on them. On the other hand, leafy vegetables that might be infested should not be eaten, as fish and meat should not be consumed, both from a health and a kashrut perspective. Milk, butter and cheeses should not be consumed unless there is absolutely nothing else available and even then they should first reach out to the IDF Rabbinate kashrut division for guidance. Baked goods like tortillas can be allowed in such situations relying on the allowances of pat akum.

According to the IDF Rabbinate, utensils (ie pots and pans, dishes, etc) found in the homes in Gaza can be used cold for eating cold foods and there would be no need to kasher the dishes. If one wants to use the utensils for eating hot foods, one would first have to kasher the utensils by heating water in a non-kosher pot and doing hagala (with adding some soap). A gas oven can be kashered by cleaning it and heating it for half an hour, and then it can be used with an aluminum pan or aluminum foil.

Even during war the IDF Rabbinate is strict about "bishul yisrael" according tot he standards of the Beit Yosef (so I guess if the soldiers find a Gazan still in one of the houses they cannot have him or her cook for them), along with using only mehadrin chickens and chalak meats. Leafy vegetables supplied by the IDF are strictly bug free Gush Katif produce (even though it isnt really Gush Katif produce since the Disengagement in 2005, the name has been kept, and is especially appropriate now with the soldiers in Gaza), and other standards that ensure the IDF Rabbinate is supplying mehadrin. 

sources: Srugim and JDN