Original sentence: The war began when Iraq invaded Iran on 22 September 1980 following a long history of border disputes, demands for the overthrow of Saddam Hussein's regime, and a secret encouragement by the US administration (President Jimmy Carter, conveyed through Saudi Arabia) which was embroiled in a dispute with the new Islamic Republic of Iran
Edited sentence: The war began when Iraq invaded Iran on 22 September 1980 following a long history of border disputes, demands for the overthrow of Saddam Hussein's regime, and allegedly a secret encouragement by the US administration (President Jimmy Carter, conveyed through Saudi Arabia) which was embroiled in a dispute with the new Islamic Republic of Iran