It took a while for the words that Mayhem just spoke to sink in, but once they did everyone arrived at the same conclusion. When Colonel Mayhem said 'everything is lost' she didn't mean the gear nor the rations, she meant hope.
It was already a bad thing that zeppelins failed to arrive when they were supposed to, but the army being unable to contact the headquarters was even worse. Up until that moment Lister had thought the army refused to speak with him because of the ever present tension between the government and the military, but now he realized it wasn't that they didn't want to speak they just didn't know what to say.
"Then why don't you help us eradicate the cryptids within the city? It should make this place safer and maybe then we can join our efforts to investigate." As the city's governor it was his responsibility to keep citizens safe no matter the cost.