Iraq Shared Investment Act - Requires that amounts made available under the Iraq Security Forces Fund shall be provided as loans subject to full repayment to the U.S. government.
Amends the National Defense Authorization Act for Fiscal Year 2006 to provide that: (1) for each of FY2008-FY2009, the Secretary of Defense shall withhold from obligation and expenditure not less than 20% of the amount made available for the Commanders' Emergency Response Program until the Secretary certifies to the congressional defense committees that the government of Iraq has agreed to provide an amount equal to 20% of the amount made available under the Commanders' Emergency Response Program from its own resources to be used to enable military commanders in Iraq to respond to urgent humanitarian relief and reconstruction requirements; and (2) if the Secretary is unable to make such certification the amount withheld from obligation and expenditure shall be available for national debt reduction.