"It's different from previous wars, because this time all the shinobi nations are allied against another threat. They're dangerous, but at least we've managed to unite all the separate forces." Time to downplay the war. Chouji doesn't want Makie worrying any more than she already will. And the number of casualties they've taken... his teammates' fathers...

The only way Chouji manages knowing that the war is half over and awaiting his return is by putting it on hold completely. He can't think too hard about it here.

And he does believe in Naruto, in all of the comrades fighting by his side. He has to believe they'll win, or there's nothing for any of them to go back to. Everyone from his world would be in the same position as Neji, as Asuma-sensei, as Kushina-san and the Yondaime, but without even the hope of life going on for those they love.