In accordance with the principles of doublethink, the aim of modern warfare in 1984 is to use up what is produced by society and to prevent an elevation in the standard of living. Though people in the past looked forward with great anticipation to the time when machinery made drudge work obsolete and when hunger and poverty could be alleviated, this never happened in the world portrayed in 1984. This type of progress threatened the existence of a hierarchical society because if everyone had the same wealth, they would demand more egalitarianism.
The society in 1984 is only possible when poverty and ignorance allow the existence of a hierarchical society. In order to destroy the excess goods produced by machinery, it is necessary for Oceania and the other world powers to continually conduct war, as war destroys what humans produce. In a world of austerity, the relative ease of the life of members of the Inner Party can be distinguished from the hardships of members of the Outer Party, and members of the Outer Party live in a better way than the "proles." In this system, surplus is destroyed in a way that is acceptable to the society.
The aim of warfare was to maintain a continual state of emergency as a way to guarantee authoritarianism. By continually being at war with one another, the three superpowers kept a balance of power, they kept the people toiling at making war supplies and at fighting, they kept the people too busy, worried, and confused to scrutinize what the governments were doing. As long as there was fighting going on, there were jobs for the proletariats. Also, as long as there was fighting going on, the population numbers could be kept down somewhat. The main concept among the three powers was the concept that the past was changeable, i.e., the "mutability of the past". This allowed history to be changed at will to be in accordance with the present. As long as no one could prove any allegation against the governments by citing some doctrine or statistic or event from the past, then the governments remained in power and impervious.