In 2008, Barack Obama promised that he would not use signing statements, but last night he released one to accompany his signing of the National Defense Authorization Act for Fiscal Year 2013.

Here's Obama's pledge:

He said that signing statements are a presidential power grab, and made clear he believed it violated the Constitution.

Overnight, however, Obama released this signing statement, in an attempt to try to change the meaning of the defense bill Congress sent to him for his signature:

THE WHITE HOUSE   Office of the Press Secretary                          For Immediate Release         January 2, 2013  STATEMENT BY THE PRESIDENT   Today I have signed into law H.R. 4310, the "National  Defense Authorization Act for Fiscal Year 2013."  I have  approved this annual defense authorization legislation, as  I have in previous years, because it authorizes essential  support for service members and their families, renews vital  national security programs, and helps ensure that the  United States will continue to have the strongest military  in the world.     Even though I support the vast majority of the provisions  contained in this Act, which is comprised of hundreds of  sections spanning more than 680 pages of text, I do not agree  with them all.  Our Constitution does not afford the President  the opportunity to approve or reject statutory sections one by  one.  I am empowered either to sign the bill, or reject it, as  a whole.  In this case, though I continue to oppose certain  sections of the Act, the need to renew critical defense  authorities and funding was too great to ignore.   In a time when all public servants recognize the need to  eliminate wasteful or duplicative spending, various sections in  the Act limit the Defense Department's ability to direct scarce  resources towards the highest priorities for our national  security.  For example, restrictions on the Defense Department's  ability to retire unneeded ships and aircraft will divert scarce  resources needed for readiness and result in future unfunded  liabilities.  Additionally, the Department has endeavored to  constrain manpower costs by recommending prudent cost sharing  reforms in its health care programs.  By failing to allow  some of these cost savings measures, the Congress may force  reductions in the overall size of our military forces.    Section 533 is an unnecessary and ill-advised provision,  as the military already appropriately protects the freedom of  conscience of chaplains and service members.  The Secretary of  Defense will ensure that the implementing regulations do not  permit or condone discriminatory actions that compromise good  order and discipline or otherwise violate military codes of  conduct.  My Administration remains fully committed to  continuing the successful implementation of the repeal of Don't  Ask, Don't Tell, and to protecting the rights of gay and lesbian  service members; Section 533 will not alter that.   Several provisions in the bill also raise constitutional  concerns.  Section 1025 places limits on the military's  authority to transfer third country nationals currently held at  the detention facility in Parwan, Afghanistan.  That facility is  located within the territory of a foreign sovereign in the midst  of an armed conflict.  Decisions regarding the disposition of  detainees captured on foreign battlefields have traditionally  been based upon the judgment of experienced military commanders  and national security professionals without unwarranted   interference by Members of Congress.  Section 1025 threatens to  upend that tradition, and could interfere with my ability as  Commander in Chief to make time-sensitive determinations about  the appropriate disposition of detainees in an active area of  hostilities.  Under certain circumstances, the section could  violate constitutional separation of powers principles.  If  section 1025 operates in a manner that violates constitutional  separation of powers principles, my Administration will  implement it to avoid the constitutional conflict.   Sections 1022, 1027 and 1028 continue unwise funding  restrictions that curtail options available to the executive  branch.  Section 1027 renews the bar against using appropriated  funds for fiscal year 2012 to transfer Guantanamo detainees into  the United States for any purpose.  I continue to oppose this  provision, which substitutes the Congress's blanket political  determination for careful and fact-based determinations, made by  counterterrorism and law enforcement professionals, of when and  where to prosecute Guantanamo detainees.  For decades,  Republican and Democratic administrations have successfully  prosecuted hundreds of terrorists in Federal court.  Those  prosecutions are a legitimate, effective, and powerful tool in  our efforts to protect the Nation, and in certain cases may be  the only legally available process for trying detainees.   Removing that tool from the executive branch undermines our  national security.  Moreover, this provision would, under  certain circumstances, violate constitutional separation of  powers principles.   Section 1028 fundamentally maintains the unwarranted  restrictions on the executive branch's authority to transfer  detainees to a foreign country.  This provision hinders the  Executive's ability to carry out its military, national  security, and foreign relations activities and would, under  certain circumstances, violate constitutional separation of  powers principles.  The executive branch must have the  flexibility to act swiftly in conducting negotiations with  foreign countries regarding the circumstances of detainee  transfers.  The Congress designed these sections, and has here  renewed them once more, in order to foreclose my ability to shut  down the Guantanamo Bay detention facility.  I continue to  believe that operating the facility weakens our national  security by wasting resources, damaging our relationships with  key allies, and strengthening our enemies.  My Administration  will interpret these provisions as consistent with existing  and future determinations by the agencies of the Executive  responsible for detainee transfers.  And, in the event that  these statutory restrictions operate in a manner that violates  constitutional separation of powers principles, my  Administration will implement them in a manner that avoids  the constitutional conflict.   As my Administration previously informed the Congress,  certain provisions in this bill, including sections 1225, 913,  1531, and 3122, could interfere with my constitutional authority  to conduct the foreign relations of the United States.  In these  instances, my Administration will interpret and implement these  provisions in a manner that does not interfere with my  constitutional authority to conduct diplomacy.  Section 1035,  which adds a new section 495(c) to title 10, is deeply  problematic, as it would impede the fulfillment of future U.S.  obligations agreed to in the New START Treaty, which the Senate provided its advice and consent to in 2010, and hinder the  Executive's ability to determine an appropriate nuclear force  structure.  I am therefore pleased that the Congress has  included a provision to adequately amend this provision in  H.R. 8, the American Taxpayer Relief Act of 2012, which I will  be signing into law today.   Certain provisions in the Act threaten to interfere with  my constitutional duty to supervise the executive branch.   Specifically, sections 827, 828, and 3164 could be interpreted  in a manner that would interfere with my authority to manage  and direct executive branch officials.  As my Administration  previously informed the Congress, I will interpret those  sections consistent with my authority to direct the heads of  executive departments to supervise, control, and correct  employees' communications with the Congress in cases where such  communications would be unlawful or would reveal information  that is properly privileged or otherwise confidential.   Additionally, section 1034 would require a subordinate to submit  materials directly to the Congress without change, and thereby  obstructs the traditional chain of command.  I will implement  this provision in a manner consistent with my authority as the  Commander in Chief of the Armed Forces and the head of the  executive branch.   A number of provisions in the bill -- including  sections 534(b)(6), 674, 675, 735, 737, 1033(b), 1068, and  1803 -- could intrude upon my constitutional authority to  recommend such measures to the Congress as I "judge necessary  and expedient."  My Administration will interpret and implement  these provisions in a manner that does not interfere with my  constitutional authority.        BARACK OBAMA  THE WHITE HOUSE,      January 2, 2013.