It needs war in order to exist, because the ego is a state of conflict.
On the one hand, it would intensify the sense of trying to get rid of a perceived enemy completely, but on the other hand, if it were to actually have "no enemies" the entire ego thought system would disappear.
The ego is in need of "unresolvable war", which stems from a state of separation which can never be resolved.
It needs a split mind and it needs the mind to be against itself. It will encourage an increase in the split, which means an increase in how much two sets of enemies seem to be at war with each other, but at the same time this separation between them acts to keep them apart.
They become like vicious animals barking at each other from behind a fence.
The ego doesn't want to use war in order to destroy its enemies. It is its own enemy, and its war is taking place within itself, by itself, to itself. But it does want "constant war without end", which requires that in some way, it wants to NOT destroy its enemies.
War without end does NOT mean it wants the total 100% destruction of the opposition, it means it wants to PRETEND that it does, only to hold back just enough to maintain the separation and keep the war going. It would even allow concessions to its enemies in secret to allow them to gain an upper hand at times, in order to preserve the split mind.
For the ego to attempt to destroy its enemies at the same time as keeping them, is testament to how IMPOSSIBLE the ego is and how INSANE it is. It is trying to achieve two completely opposite goals at once. That is because the ego is a belief in an opposite to love - the possibility of real love and real death existing simultaneously.
While the ego fixates on death, and death seems to be an end, it is but a way to continue illusions and is quickly followed up with birth. If the ego really wanted death to be "the end" there would be no births.
The ego simply wants to always be in a state of conflict, a tug of war, where it is complete confused about what it wants, where it believes that two completely opposite goals are coexisting and achievable, and wants to keep its enemies as much as it wants to get rid of them, meaning, it wants to keep SUFFERING for as long as possible.
This is also why in special relationships, where there is special hate and special love, where you attempt to steal love from the other and destroy them because of what they have which you lack, and yet you want them to keep that special something so you can idol worship them. Impossible opposing goals.
This is why the world is just spinning its wheels. A little death here, a little birth there, and generally lots of suffering, tension and conflict all the time. Perpetual war without end, a war not too severe as to wipe out the ego entirely, but just enough to make it seem like this is what the ego wants. It's no wonder this world is insane and disappears up its own arse.