1984 how is perpetual war no different than perpetual peace why does the inner pary alter the past

In Orwell's novel 1984, there is no  difference between perpetual war and perpetual peace.  For members of the inner party, perpetual war - which is everlasting by definition - does not allow for any changes in society.  The inner party changes or alters historical records of the past for a particular reason: people often make decisions about their present based upon incidents from the past.  By controlling the past, and the records and narratives related to it, the inner-party can control the way people thinking about the past, they can control how people think about the current day and the future.