Obviously. the first Mad Max film is pre apocalyptic (apparently the back on the DVD says events of Mad Max 2/Road Warrior took place 3 years after the first movie). In the first film, we can see that there is obviously SEVERE economic difficulties:
- Scarcity of fuel.
- Run down police headquarters that are near ruins.
- Lack of funding for cars and having to get a millionaire businessman to try and buy Max to stay in the police.
Yes, it is obvious the world is in a severe recession WORSE than the current one obviously! BUT in the second film, it is implied that while war and/or negotiations to avoid/halt it (quote: they talked and they talked ... ) are going on in the world, the events of Mad Max 1 are happening at the same time (quote: on the roads, it was a white line ...). So, the war between two superpowers (presumably, the US and USSR/Russia) was beginning or about to happen during Mad Max 1 (caused by a oil-related recession maybe triggered by a regional Mid East war). By Mad Max 2, the war was either over or in its last and fatal stages. In Mad Max 2, it is implied that there are still coastal areas of Australia that are okay but Max (after losing his wife) is not at all interested in this for HIMSELF but is helping others to go there. So, the wasteland Max lives in is the worst of the post-apocalypse world and one Max self-exiled himself to even as early as the first movie when he is seen driving away. Petrol/oil is still in evidence as are cars and motorcycles. There is NO mention either here of NUCLEAR conflict. Maybe, the war is on and has ruined nations and the economy of the world but has YET to go nuclear?
The Iran-Iraq war and the potential entering in of superpowers to back up these two countries seems to have inspired the film. Also, the reference to the word Ayatollah in the film by the biker gangs seems to imply their memory of Middle Eastern and in particular Iraqi and Iranian issues!
By Mad Mad Beyond Thunderdome, it is obvious that ALL oil based fuel is gone. And that NUCLEAR war has happened. The fallout detector Max has to test the water from the salesman shows the water to be radioactive. Also, the Atomic Cafe! By now, the war that may have started out as an oil related conflict in Iraq or Iran for example has turned into a world war with superpowers suck in and one that ended up global and nuclear. Clearly, this has happened LONG before the events of the third Mad Max movie as the children in it were born after the events. Also, Max looks a LOT older and his clothes too!
We see ruins of a deserted Sydney and tales of an air crash where people attempted to get away from a city (presumably Sydney) so it is clear that ALL the former world civilisation has ended. Still though there are safer areas near the coasts as in the second movie and Max once again gets his friends there while he himself prefers to remain in the wasteland. It is implied a new civilisation is started by Max's friends in what was Sydney.