At their best, NIEs provide a careful assessment of an international situation based on extensive collection and careful analysis that provides policymakers with insights into the opportunities and risks that the United States will face. On occasion, U.S. policies have not been coordinated throughout the executive branch or with Congress. There are other inherent limitations to the NIE process. Furthermore, it has been argued that NIEs are not necessarily the most important contribution of intelligence agencies, which produce thousands of assessments of varying complexity in a given year. Congress has from time to time informally requested NIEs (as was the case with the NIE on Iraqi WMDs produced in 2002, as discussed below), but the House intelligence authorization bill ( H.R. Congress included a requirement for an NIE on Iran in the FY2007 Defense Authorization Act ( P.L. 109-364 , §1213) to be submitted in classified form. The statute also stated that, "Consistent with the protection of intelligence sources and methods, an unclassified summary of the key judgments of the National Intelligence Estimate should be submitted." Most felt "sandbagged" by the Intelligence Community. Because, however, much of the public debate focused on Iraq's then-current WMD capabilities, the leadership of the Senate Intelligence Committee asked for an NIE "on the status of Iraq's programs to develop weapons of mass destruction and delivery system, the status of the Iraqi military forces, including their readiness and willingness to fight, the effects a U.S.-led attack on Iraq would have on its neighbors, and Saddam Hussein's likely response to a U.S. military campaign designed to effect regime change in Iraq." The NIE was requested on an immediate basis. An unclassified White Paper, containing many of the NIE's judgments, was issued shortly thereafter. P.L. NIE on Iranian Nuclear Intentions and Capabilities

On December 3, 2007, the Office of the Director of National Intelligence released unclassified Key Judgments of an NIE prepared in November 2007, Iran: Nuclear Intentions and Capabilities . The Key Judgments of the 2007 NIE state that "We judge with high confidence that in fall 2003, Tehran halted its nuclear weapons program; we also assess with moderate-to-high confidence that Tehran at a minimum is keeping open the option to develop nuclear weapons." Conclusion: Useful Products if Limitations Appreciated

Congress is and will continue to be an important consumer of national intelligence, but there are concerns that mandating NIEs may not support the legislative process to the extent that some have anticipated. Similarly, Section 1240 of the FY2012 Defense Authorization bill, passed by both chambers in December 2011, requires a report from the Secretary of Defense "in coordination with the Director of National Intelligence" on Russian nuclear forces by March 2012.
National Intelligence Estimates (NIEs) are often of considerable interest to many Members of Congress. They represent the most formal assessment of a given national security issue by the U.S. intelligence community. The intelligence process, however, is not an exact science and, on occasion, NIEs have proved unreliable because they were based on insufficient evidence or contained faulty analysis. This was demonstrated in the NIE produced in 2002 on Iraqi Weapons of Mass Destruction, parts of which were significantly inaccurate.
At best NIEs provide an in-depth understanding of a complex international situation where U.S. policymakers may perceive a need to make difficult decisions. Although NIEs can provide insights into the likely effects of certain policy approaches, they are not usually prepared to take into account the details of planned U.S. diplomatic, economic, military, or legislative initiatives.
Traditionally, Congress has not been a principal consumer of NIEs. Although Congress has on occasion requested NIEs and expressed interest in their conclusions, the experience with the NIE on Iraqi WMD and other assessments has led some Members to question their usefulness. The FY2007 Defense Authorization Act (P.L. 109-364, §1213) specifically requested a comprehensive NIE on Iran. The NIE was to be prepared in classified form and an unclassified summary of key judgments forwarded, "consistent with the protection of intelligence sources and methods." In early December 2007 the DNI released unclassified key judgments of a NIE, Iran: Nuclear Intentions and Capabilities. The NIE judged "with high confidence that in fall 2003, Tehran halted its nuclear weapons program." Even though the NIE did recognize "with moderate-to-high confidence that Tehran at a minimum is keeping open the option to develop nuclear weapons," the public release of the key judgments at a time of ongoing diplomatic initiatives was widely considered problematical.
There seems to be an emerging consensus that publicly releasing NIEs, or even unclassified summaries, has limitations. Some of the nuances of classified intelligence judgments are lost and there are concerns that public release of an unclassified summary of a complicated situation does not effectively serve the legislative process. In passing the FY2010 Defense Authorization Act (P.L. 111-84), Congress chose not to require an NIE on the nuclear ambitions of certain states and non-state actors, but rather to request biennial reports (with unclassified summaries) from the DNI. Similarly, the FY2012 Defense Authorization bill, H.R. 1540, passed by both chambers in December 2011, requires a report on Russian nuclear forces to be prepared by the Secretary of Defense "in coordination with the Director of National Intelligence."