How does the Party/Big Brother use war as a method of control in George Orwell's 1984?

In 1984, war is a constant presence in the lives of the people of Oceania. It is used by the party in two important ways.

First of all, war is used to increase people's loyalty towards the party. In Part 2, Chapter 9, for instance, Winston describes Hate Week, a week-long event which is designed to strengthen hatred against the party's current enemy, Eurasia. During this time, the people of Oceania sing songs, march and...

In 1984, war is a constant presence in the lives of the people of Oceania. It is used by the party in two important ways.

First of all, war is used to increase people's loyalty towards the party. In Part 2, Chapter 9, for instance, Winston describes Hate Week, a week-long event which is designed to strengthen hatred against the party's current enemy, Eurasia. During this time, the people of Oceania sing songs, march and demonstrate against Eurasia to the point of mania. As Winston comments:

“After six days of this, when the great orgasm was quivering to its climax and the general hatred of Eurasia had boiled up into such delirium that if the crowd could have got their hands on the 2,000 Eurasian war-criminals who were to be publicly hanged on the last day of the proceedings, they would unquestionably have torn them to pieces.”

By demonizing Eurasia, the people of Oceania feel united and this contributes to their overall loyalty towards and love of Big Brother.

The Hate Week celebrations also show us a second way in which the party uses war to control people. Right in the middle of Hate Week, the party suddenly announces a switch in the enemy: Eurasia is now the ally and Oceania is at war with Eastasia. This declaration prompts a flurry of activity as the party rewrites history and erases all traces of war with Eurasia:

 "A large part of the political literature of five years was now completely obsolete. Reports and records of all kinds, newspapers, books, pamphlets, films, sound-tracks, photographs -- all had to be rectified at lightning speed."

The fact that the party can manipulate information in this manner is illustrative of its control over the population. Everything they see, read and hear is dictated to them by the party. Even if they notice this sudden change in the enemy, they can never verbalize it for fear of committing thoughtcrime and facing the death penalty.