US forces officially withdrew from their remaining bases in Iraq on Wednesday, September 30, concluding a long-term military presence. This withdrawal has prompted concerns about a potential security vacuum within Iraq, creating opportunities for both Iranian-backed militias and the Islamic State group to strengthen their positions. Tehran and its allies are celebrating the departure as a significant victory. The agreement for this withdrawal was initially reached in 2024 during the presidency of Joe Biden, but was implemented by the administration of Donald Trump despite ongoing tensions with Iran. Iran maintains considerable influence in Iraq through various proxy groups. The departure raises fears that the Islamic State group will be able to reorganize and regain a foothold in the region.