BAGHDAD, Sept. 25 -- When the last American soldiers board their transports out of Iraq on September 30, the country's most heavily armed non-state factions will still be holding their weapons. Under Baghdad's latest plan, they will be allowed to keep them for another nine months.

Iraqi Prime Minister Ali al-Zaidi announced this week a revised disarmament framework giving the country's Iran-backed Popular Mobilization Forces until June 30, 2027, to formally place their weapons under state authority. The announcement, made on the sidelines of the United Nations General Assembly in New York, came after al-Zaidi's government was forced to retreat from a sharper earlier deadline that the militias had refused publicly and without hesitation....