Is Iran’s past – its habit of cheating on its international nuclear agreements -- prologue? Should the Obama Administration accept Iran’s lies about its earlier efforts to design and develop a bomb in exchange for insisting on its strict compliance with the new deal it has made limiting the size, scale and nature of its nuclear program?

This is the crucial issue at stake when the United Nations’ nuclear watchdog, the Vienna-based International Atomic Energy Agency, meets Tuesday to remove the last obstacles to lifting sanctions against Iran and unfreezing some $100 billion in Iran’s oil revenue in banks throughout the world.

On December 15th the Agency’s 35-member board of governors is expected to approve a resolution dropping questions about Iran’s previous nuclear activities despite unresolved issues regarding the military dimensions of Tehran’s program—which the IAEA has now established beyond reasonable doubt.

Administration officials say the concession is worth it, that lifting sanctions in exchange for limiting Iran’s nuclear activities for the next 10-15 years justifies overlooking the regime’s refusal to confess its previous nuclear sins.

The draft resolution that the IAEA governors are expected to approve states that despite such omissions and half-truths, Iran has provided sufficient information and access about its earlier weapons work to “close the file” on its previous nuclear program.

In fact, experts and other sources say, the U.S. has already quietly challenged, with some success, several attempts by Iran to weaken the deal’s constraints.  Two areas of dispute said to have been resolved largely in Washington’s favor concern first, what level of enriched uranium Iran will be permitted to retain and second, what kind of support equipment Iran must dismantle along with the centrifuges capable of turning uranium into bomb fuel.

Skeptics of the deal-- known as the Joint Comprehensive Plan of Action-- and the IAEA “road map” outlining what Iran must do before sanctions are lifted, argue that permitting Iran to dissemble and hide information about previous weapons-related work may prompt Tehran to conclude that it will be able to pay no price for cheating in the future as well as the past. 

Overlooking Iranian stonewalling about aspects of its earlier work, they say, not only makes it harder to devise an effective monitoring scheme for Iran’s current nuclear program, but also establishes a terrible precedent for arms control accords with other states. Because Washington and its allies are permitting Iran to begin implementing the new deal and get sanctions lifted with a lie, Iran’s past cheating is destined to be prologue.

While he continues to support the agreement, even Robert Einhorn, a senior fellow at Brookings who helped negotiate the deal, calls the trade-off between the past and present “untidy.” “It will leave many past issues unresolved,” he wrote in the National Interest.  

The deal struck in July between Iran and the U.S. and its nuclear allies, the so-called P-5 plus 1, significantly scales back the breadth and depth of Tehran’s nuclear activities for a decade at least. Experts say that in accordance with the treaty, Iran has already taken off line some 5,000 of 13,000 centrifuges and has been making arrangements to ship out of the country uranium that could be enriched to fuel a bomb.

But the IAEA’s report in early December on its earlier nuclear weapon design programs concludes that Tehran has not given the IAEA complete, truthful answers about its earlier activities.  With astonishing clarity, the agency assesses that Iran not only systematically pursued nuclear weapons until 2003, but continued doing so sporadically until 2009 – later than the some western intelligence agencies estimate. At the same time, the IAEA found no credible evidence of recent weapons-related activity, or that Iran got far in its bomb-making.

The IAEA report states that Iran provided only partial or incorrect answers to some questions about efforts to design and test components of a nuclear weapon design (as distinct from the process of enriching the component nuclear material). Specifically, it concludes, Iran’s cover up has “seriously undermined the agency’s ability to conduct effective verification” at Parchin, a military site where Iran is thought to have tested implosion devices in a now-missing chamber. Based partly on a visit there which did not conform to usual Agency inspection procedures, satellite imagery and sampling at the site conducted by Iran but supervised remotely by the IAEA, inspectors dispute Iran’s assertions that only chemical weapons were stored there. The evidence to date, the report declares, “does not support Iran’s statements.”

Secretary John Kerry downplayed the importance of such findings, asserting bizarrely that America’s “perfect” intelligence about Iran’s past nuclear effort ensures that the agency has a good grasp of how far Iran got, and therefore, has been able to devise monitoring that will make it difficult for Iran to cheat.

Some inspectors and experts disagree. “Absent a complete understanding of the extent and scope of Tehran’s nuclear-weapons work,” warns Olli Heinonen, a 20-plus-year veteran of the IAEA now at Harvard’s Belfer Center, “effective verification will be compromised.” Sanctions should not be lifted, he argues, until Iran “has met its nuclear obligations.” And because sanctions have not yet been lifted, argues William Tobey, also a Belfer scholar who helped manage America’s nuclear weapons arsenal under President George W. Bush, this is the moment of maximum American leverage.    

Due to the belated concessions that Washington and its allies made to Teheran in drafting the agreement and roadmap, however, the IAEA’s examples of Iran’s stonewalling and duplicity don’t matter.  The draft resolution that the IAEA governors are expected to approve states that despite such omissions and half-truths, Iran has provided sufficient information and access about its earlier weapons work to “close the file” on its previous nuclear program.

Einhorn argues that the administration deliberately set the reporting bar on past nuclear efforts low, since it concluded that Tehran would continue refusing to acknowledge cheating given its Supreme Leader’s fatwa that Islam forbids nuclear weapons. Plus, defenders argue, another section of the resolution requires Iran to “cooperate fully” with IAEA monitoring and verification programs, which they interpret to mean that if new information turns up which conflicts with Iran’s assertions, the file on past programs can be reopened. But by then, sanctions will have been lifted.

Iran has already been pushing America’s patience – by having tested in violation of  U.N. resolutions an intermediate range ballistic missile capable of carrying a nuclear weapon, by imprisoning U.S. citizens of Iranian origin, including Washington Post reporter Jason Rezaian, and by engaging in other human rights violations and provocative acts.

This is not a subtle matter. The Iranian government is, history tells us, given to compulsive haggling. A deal is never done, but a work in progress. But whether analysts support or oppose the deal, most agree on this: the U.S. and its allies should do more now to persuade Iran that lies and cheating, past or present, will not be tolerated. The IAEA’s governors should keep the issue of Iran’s past program on its agenda. For the sake of American national security and efforts to stop the spread of nuclear weapons, this time the U.S. must not be out-haggled.       

Charles Duelfer was Deputy Executive Chairman of UNSCOM from 1993 to 2000 and the head of CIA's Iraq Survey Group, which produced the definitive document on Saddam and his WMD programs in 2004.

Judith Miller, a Fox News contributor, is an award-winning writer and author, and an adjunct fellow at the Manhattan Institute. The author of several books, her latest is "The Story: A Reporter's Journey" (Simon & Schuster, April 7, 2015) now available in paperback. Follow her on Twitter @JMFreeSpeech.