Enhancing Oversight and Security at United States Missions Act of 2010 - Directs the Secretary of State to submit a plan to Congress to increase oversight of private security contractors by U.S. government personnel at U.S. missions where the Armed Forces are engaged in combat operations in order to ensure that security functions are appropriately performed. Requires such plan to be implemented within 180 days after the enactment of this Act.
Requires the Secretary to: (1) periodically review the performance of such contractors to ensure that security functions are performed in a manner that is consistent with plan requirements; and (2) report annually to Congress, in each of 2011 through 2015, on the results of the most recent performance review.