This is a print on demand edition of a hard to find publication. Somali pirates operating off the Horn of Africa have attacked more than 450 ships and taken nearly 2,400 hostages since 2007. A small number of U.S.-flagged vessels and ships have been among those affected. As Somalia lacks a functioning government and is unable to repress piracy in its waters, the National Security Council developed an interagency Action Plan in December 2008 to prevent, disrupt, and prosecute piracy off the Horn of Africa in collaboration with international and industry partners. This report evaluated the extent to which U.S. agencies: (1) have implemented the plan, and any challenges they face in doing so; and (2) have collaborated with partners in counter-piracy efforts. Includes recommendations. Charts and tables.