1984 Journal 2

"On the sixth day of Hate Week, after the processions, the speeches, the shouting, the singing, the banners, the posters, the films, the waxworks, the rolling of drums and squealing of trumpets, the tramp of marching feet, the grinding of the caterpillar of tanks, the roar of massed planes, the booming of guns-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 two thousand Eurasian war criminal who were to be publicly hanged on the last day of the proceeding, they would unquestionably have torn them to pieces-at just this moment it had been announced that Oceania was not after all at war with Eurasia. Oceania was at war with Eastasia. Eurasia was an ally." - Orwell 148

In Orwell's nightmarish society, the people are controlled completely by propaganda. Hate Week is propaganda at its worse. The people are convinced by the media and their peers that one country and its people are the worst people on the planet, and should be killed. This detracts any other emotion out of the people, so they cannot aim it at anything else in their lives. They are so emotionally controlled that when they are told that someone else is actually the enemy, they have no problem is turning their hate instantaneously. This whole frenzy is leading to Winston's reading of Goldstein's book. In the book Winston finds out the true meaning behind Hate Week and the wars, although he already does know himself. The wars and the hate are simply a way of keeping the people under control. With the only emotion in their minds being hate towards are certain country, they are no longer able to make rational thought processes, destroying the possibility of resistance to their own government. He also finds out that the wars are endless. There is no true ally or enemy, and it is constantly switching, just as he has witnessed. The war is simply a way of keeping the people down.