There are lot of references that would be familiar to someone at the time the book was written. It implies that it's describing the inevitable results of politics in the late 40s as they would unfold 40 years into the future.

It's very confusing to see that aspect of the book if you read it thinking that 1984 is far in the past. When the book was new, 1984 was far in the future - like a book about 2060 today.