Setting of Mad Max from first movie to second/third

Question

I believe from the hints in the original Mad Max movie and the intro from the second Mad Max movie that the original Mad Max movie was placed after the decline-of-society-events (later established as a nuclear war over energy resources in 2 and 3). The hints in the original movie seem to be:

• The police station seems worn down and wrecked beyond what one might expect
• Populations seem extremely limited, sparse (As a counter: could be either just Australia or limited production budget)
• The government's ability to respond to crime seemed extremely limited
• Government overall seemed relatively unorganized and make-shift

Yet even so the original Mad Max setting seemed more or less modern civilization (it was a place where people took vacations from their job, and could reasonably expect ice cream shops to be on beaches), yet in Mad Max 2 and 3 society is instead near comical levels of post-apocalyptic with only barbaric traces of modern society remaining.

Further, the intro of Mad Max 2 seems to establish the apocalyptic events happening before Mad Max 1. In the intro narration it's said that (portions removed to shorten the passage):

...two mighty warrior tribes went to war... Their world crumbled. The cities exploded. A whirlwind of looting, a firestorm of fear. Men began to feed on men. On the roads it was a white line nightmare. Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice. And in this maelstrom of decay, ordinary men were battered and smashed... men like Max... the warrior Max. In the roar of an engine, he lost everything...

Ignoring the titular character, the original Mad Max and the two sequels seem to be in entirely distinct, separate universes.

Is there an in-universe explanation for this apparent discrepancy?

(Note: I haven't seen Fury Road yet, so perhaps that explains something. If there's answers there, feel free to draw from it for your answer without fear of spoiling)

Answer 1

The explanation is in the part of the quote that you omitted:

Narrator: My life fades. The vision dims. All that remains are memories. I remember a time of chaos... ruined dreams... this wasted land. But most of all, I remember The Road Warrior. The man we called "Max." To understand who he was, you have to go back to another time... when the world was powered by the black fuel... and the desert sprouted great cities of pipe and steel. Gone now... swept away. For reasons long forgotten, two mighty warrior tribes went to war, and touched off a blaze which engulfed them all. Without fuel they were nothing. They'd built a house of straw. The thundering machines sputtered and stopped.

Their leaders talked and talked and talked. But nothing could stem the avalanche.

Their world crumbled. The cities exploded. A whirlwind of looting, a firestorm of fear. Men began to feed on men. On the roads it was a white line nightmare. Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice. And in this maelstrom of decay, ordinary men were battered and smashed... men like Max... the warrior Max. In the roar of an engine, he lost everything... and became a shell of a man... a burnt-out, desolate man, a man haunted by the demons of his past, a man who wandered out into the wasteland. And it was here, in this blighted place, that he learned to live again. –IMDB

There is no discrepancy. There is an ever decreasing amount of what's left of what was. These are not separate universes, it's a continuation of a dystopian society's descent into a post-apocalyptic world.

Mad Max takes place somewhere between building this "house of straw" and when the "thundering machines sputtered and stopped."

This intro establishes the apocalyptic events happening before Mad Max 1 that the world was headed irreversibly into a further state of dystopia, which culminated in global thermonuclear war.

If you can still get ice-cream, and gasoline at the pump, 'it' hasn't happened yet. Because as we all know, "Ice is civilization."

Do not confuse the 'decline of society' with all out nuclear war. One could say that the first movie takes place in present day; ever been to Detroit, or heard of ISIS? Are we not currently, in our own :

"maelstrom of decay"

Fury Road was lauded for explaining nothing, so I wouldn't bother trying to find any insight there. The Narrator's intro covers everything; front to back. Indeed however, these settings are quite distinct. The first movie was before, everything else is after.

Answer 2

@Mazura is spot on. In the first film society is in terminal decay leading to an apocalypse which takes place between Mad Max and The Road Warrior.

Mad Max: Dystopia.

The Road Warrior: Post Apocalypse.

Beyond Thunderdome: Post Apocalypse.

Fury Road: Post Apocalypse.

The prologue of the Fury Road prequel comic chronicles the events of the first three films, the breakdown of society - the apocalypse - the post apocalypse.