From an ideological point of view, Justinians attempted Restauratio imperii was quite reasonable. The Roman Empire without Italy, without Rome, without the half of its ancient territory doesn't look that impressive so to say. But this is mere ideology. Justinians invasion of Italy ruined the Italian economy, and Justinian's conquests (which neither were nor could be a complete reconquest of the WRE) were lost soon after his death.
Now imagine a world in which Justinian acts differently. He accepts that he can't retake in his lifetime what Rome conquered within several centuries. He concentrates on domestic politics (more peaceful management of the Nika riots, Corpus Iuris Civilis and the different monuments like the Hagia Sophia), an "inner restauration" so to say. The plague and the earthquake in Constantinople happen as OTL.
Even with the plague, Justinian has still plent of ressources (money, manpower...) available he threw to the west in OTL. How can he use these ressources ITTL to strenghten the Empire? Would he be able to prevent the Arabian expansion (Islam would likeley be butterflied away anyway) and the Slavic conquests? Would Byzantium be better off without Justinian's conquests?
Now imagine a world in which Justinian acts differently. He accepts that he can't retake in his lifetime what Rome conquered within several centuries. He concentrates on domestic politics (more peaceful management of the Nika riots, Corpus Iuris Civilis and the different monuments like the Hagia Sophia), an "inner restauration" so to say. The plague and the earthquake in Constantinople happen as OTL.
Even with the plague, Justinian has still plent of ressources (money, manpower...) available he threw to the west in OTL. How can he use these ressources ITTL to strenghten the Empire? Would he be able to prevent the Arabian expansion (Islam would likeley be butterflied away anyway) and the Slavic conquests? Would Byzantium be better off without Justinian's conquests?