One of the first things God created after Heaven and Angels (Job 38) was choice and free will. In order for all things to be perfected, in addition to choice you have to have something to choose from, which is evil.
Isaiah 45:6–7
6 That they may know from the rising of the sun, and from the west, that there is none beside me. I am the Lord, and there is none else.
7 I form the light, and create darkness: I make peace, and create evil: I the Lord do all these things.
All of Gods creations have the right to choose, they are not forced into their choice, but there are consequences for the choice.
Lucifer made a choice as did the angels that followed him. Without choice the heart of a man is not known to him. There must be a tangible choice between something, and this choice was given to all creatures.
War in Heaven was a result of vanity and the evil it evolves into, Lucifer and the other Angels did not have to make the choice they did, anymore than any man who makes the choices that he does.
Since God is in Heaven and creation started there, the origins of these choices took place in Heaven. Lucifers choice, the war, all took place in Heaven, prior to earths foundations being formed.
The foundations of the earth as recorded in Job 38, speak to the elements required to sustain life on the earth prior to man being put here. Lightning strikes, gravity, the firmament between the land and the sea, the rotation of the earth, oxygen levels etc….. there are 122 of these independent yet interdependent anthropic constants that make up the foundations of the earth which sustain life the planet.
Angels, who are referred to in Job 38 as the morning stars were created prior to the foundations being laid. This war with Lucifer and his comrades, took place after the foundations were laid and before man was placed on the earth or the creation of the Garden of Eden. For this reason, it makes sense that all things start in Heaven and later here on earth.
Job 38: 4–7
4 Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding.
5 Who hath laid the measures thereof, if thou knowest? or who hath stretched the line upon it?
6 Whereupon are the foundations thereof fastened? or who laid the corner stone thereof;
7 When the morning stars sang together, and all the sons of God shouted for joy?
Ezekiel 28:13-19
13 Thou hast been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
14 Thou art the anointed cherub that covereth; and I have set thee so: thou wast upon the holy mountain of God; thou hast walked up and down in the midst of the stones of fire.
15 Thou wast perfect in thy ways from the day that thou wast created, till iniquity was found in thee.
16 By the multitude of thy merchandise they have filled the midst of thee with violence, and thou hast sinned: therefore I will cast thee as profane out of the mountain of God: and I will destroy thee, O covering cherub, from the midst of the stones of fire.
17 Thine heart was lifted up because of thy beauty, thou hast corrupted thy wisdom by reason of thy brightness: I will cast thee to the ground, I will lay thee before kings, that they may behold thee.
18 Thou hast defiled thy sanctuaries by the multitude of thine iniquities, by the iniquity of thy traffick; therefore will I bring forth a fire from the midst of thee, it shall devour thee, and I will bring thee to ashes upon the earth in the sight of all them that behold thee.
19 All they that know thee among the people shall be astonished at thee: thou shalt be a terror, and never shalt thou be any more.
Isaiah 14:12-17
12 How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations!
13 For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north:
14 I will ascend above the heights of the clouds; I will be like the most High.
15 Yet thou shalt be brought down to hell, to the sides of the pit.
16 They that see thee shall narrowly look upon thee, and consider thee, saying, Is this the man that made the earth to tremble, that did shake kingdoms;
Revelation 12:4–8
4 And his tail drew the third part of the stars of heaven, and did cast them to the earth: and the dragon stood before the woman which was ready to be delivered, for to devour her child as soon as it was born.
5 And she brought forth a man child, who was to rule all nations with a rod of iron: and her child was caught up unto God, and to his throne.
6 And the woman fled into the wilderness, where she hath a place prepared of God, that they should feed her there a thousand two hundred and threescore days.
7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
8 And prevailed not; neither was their place found any more in heaven.