The world is divided into several Blocs, one being Oceania (Britain, the whole America, South Africa, Australia and New Zealand).

We really can't tell if the world is at perpetual war because we only get the information provided by "Big Brother" to it's citizens, and we can tell throught the book that "Big Brother" systematically lies and manipulates the information. It isn't unreasonable to think that the world isn't at war at all, and it's just a psyop.

I agree the plot itself is quite simple. The substance of the novel is the context for that plot. A techno-autoritharian surveilance state that has managed to bend its cintizenry's will through absolute control, prosecution of thought crime, manipulation of speech and recorded history and constant witch hunting and neighbour to neighbour snitching. Very fitting that the political phyllsophy of the state is called Ingsoc (short for English Socialism) considereing what we are seeing lately.

The film of the picture is a near scene-by-scene adaptation of the book. Iirc even the dialoges are word-by-word, which is in the line with other film adaptations of those days. Imho not a specially enjoyable way of adapting a film, I'd rather read the book if itms going to be done that way,