President Barack Obama's policy of a targeted, strategic counterterrorism approach succeeded in reducing the number of US troops deployed in Afghanistan and Iraq. This approach also resulted in the killing of several high-profile terrorists, including Osama bin Laden. However, the policy did not completely eliminate the threat of terrorism, and terrorist groups such as ISIS continued to pose a significant threat to the region and beyond. Additionally, the policy of drone strikes and targeted killings has been criticized for its legality and morality, and for causing civilian casualties. Furthermore, the withdrawal of US troops from Iraq in 2011 left a power vacuum that was exploited by ISIS, leading to the rise of the terrorist group and the destabilization of the region.