Thinking again about the Mortifiers' origins, how they were originally an SAS unit formed to deal with civil unrest, a bit like the MFP. But unlike the MFP, these guys aren't small town highway patrol. They've got an institutional heritage spanning three world wars and they're operating in the most dangerous urban centers in Eastern Australia. Their units have names like Ghost and Raider and Mortifier, and they consider Black Hawk Down an office drama.
I can see these guys being used not as a patrol force but as almost a SWAT team, dropping in, busting up crime rings, grabbing gang bosses and stuffing them into waiting convoys for arrest. They approach their job with a mixture of delight-- because they get to do shit and kill bad guys--and scorn, because they're not cops, so why do they keep getting cop jobs? But they are very good at what they do, and during the Water Wars they make a name for themselves.
And then something goes sour. There's a PR disaster, and despite doing everything right, a unit gets thrown under the bus to save a bigwig's political career. They find out they're being fed false information: that smuggling convoy they seized? Humanitarian aid. That gang lord they shot in front of his kids? A political dissident. That terrorist camp they blew up? 90% of the bodies were under the age of 12. They complain exactly once, and the people in power tell them to shut up and do as they're told. They've gotten too used to using the SAS as their errand boys, and a famously chaotic and intrinsically-motivated group of people decides they've had enough.
They probably don't bail all at once, at least not before the bombs drop. Sure, some of them beat feet and disappear; who are the authorities going to send after them, their own brothers? The bulk of them stay on and keep getting paid, but their efficacy mysteriously starts to drop. People with targets on their backs get tipped off. Smuggling runs get rerouted at the last minute. A government pay depot gets raided in the dead of night, and suddenly kids who haven't celebrated a holiday in years have Christmas presents. The SAS keep the peace, alright, but they keep it on their own terms.
When the Tri-Nation Nuclear War finally brings civilization to an end, they don't scatter the way the MFP does. They've been a brotherhood for over a century at this point, and they're not going to let a few hydrogen bombs change that. The survivors find each other, scrape together what they have left, and continue doing what they do best. They're the good guys, after all; they know it, and they've always known it. And if the good guys sometimes have to do bad things, well, that's also the way it's always been.
