Okay.It's an alternate world.
All weapons of war have turned into equipment to build, Not destroy. After tha last battle there was equipment laying everywhere. Lots of still operational tanks. All types from at least the four major Combatants.
They run too. Hmm modified they could be Bulldozers and Road Building equipment. Imagine operating an M1A1 as a canal cutting , tilt bladed bad Fenoroso. Neat huh ? How also using the barrel stuff with new instruments fitted to be a Demolition machine. Install a blade plow like twin snow plow blades at a sharp angle , Mount on the turret and barrel. Can you say g'bye old buildin? Or how about this. A super foaming Airport Fire machine that spits foam out of the barrel instead of bullets!
Melt the Gun barrels down and make pickup trucks out of them. Take the M113s and all they're iterations of them and rebuild them into search and rescue vehicles after a Natural Disaster. HumVees? Scrap them all or do this. Never mind their lousy gas and diesel mileage Turn them into Steel hulled airboats. For storm rescue service.