Why the Arabs attacked the Roman Empire | Anthony Kaldellis and Lex Fridman

Anthony Kaldellis discusses the historical context of Arab Muslim expansion into the Roman and Persian Empires. He begins by explaining Persian imperial ambitions under Khusrau II, who sought to revive Achaemenid-era Persian greatness by extending the empire to the Mediterranean. For Romans, this represented existential threat and survival. Kaldellis then shifts focus to Arab Muslim warfare, noting that the initial goal was unifying Arabia under Islam, after which they struck outward at both Rome and Persia. He emphasizes this was not a mystery—two recently formed and effective military forces naturally target weakened neighbors on their doorstep. The critical factor was that both empires had just finished a massive, destabilizing war with each other, leaving them depleted in manpower and resources. Crucially, neither empire had defensive preparations oriented toward Arabian threats, as Arabia had previously only produced occasional raiders. The consequences were severe: Arab forces stripped away Rome's richest provinces, particularly Egypt. The loss of Egyptian grain supplies meant Constantinople could no longer be adequately fed, leading to dramatic population decline in the following decades.