The Iran nuclear agreement is fast approaching its implementation stage despite the recent confirmation that Iran lied about its nuclear weapons efforts and did not fully cooperate with the investigation launched by the International Atomic Energy Agency (IAEA).

Last week, the IAEA released its final report on the “Possible Military Dimensions” (PMDs) of Iran’s nuclear program. It concluded that Iran maintained an organized nuclear weapons effort through 2003, and that some aspects of that work continued until at least 2009. The IAEA was not able to find evidence that the nuclear weapons work continued after that, at least in part due to Iran’s continued stonewalling of the investigation.

This finding confirms that Iran lied about its nuclear weapons efforts. Moreover, it refutes the controversial 2007 National Intelligence Estimate by the U.S. intelligence community that surmised that Tehran halted its nuclear weapons efforts in 2003. (The Heritage Foundation lambasted that flawed assessment here.)

Despite the troubling IAEA report, the Obama administration is backing a draft resolution that would close the PMD investigation, which is expected to be approved when the IAEA Board of Governors meets on December 15.

Iran has demanded that the IAEA “close the file” on its PMD investigation even though Tehran failed to cooperate with the IAEA, as required by multiple U.N. Security Council resolutions.

Iran’s supreme leader, Ayatollah Ali Khamenei, published a letter on Oct. 21 that unilaterally reinterpreted the terms of the July 14, 2015, nuclear agreement, formally known as the Joint Comprehensive Plan of Action (JCPOA). Khamenei insisted that Iran would delay fulfilling its obligations until the IAEA closed its investigation. He also insisted that the U.S. and the U.N. remove the “sanctions structure,” which includes the “snapback” mechanism at the U.N. Security Council and possibly even non-nuclear sanctions.

If Khamenei sticks to these demands, he will be throwing a monkey wrench into the implementation of the JCPOA.

Closing the IAEA investigation would be dangerous because a complete accounting of Iran’s past nuclear activities is necessary to ensure the effectiveness of future verification and inspection activities called for under the JCPOA.

The Obama administration’s longstanding promises that any nuclear agreement would include “anytime/anywhere” inspections were diluted in the JCPOA to become a more risky “sometimes/some places” arrangement in which Tehran would have up to 24 days to delay any inspections.

The administration also backtracked on its insistence that Iran come clean on its past nuclear work.

Closing the IAEA investigation would reward Tehran for its duplicity and encourage future Iranian intransigence. It would undermine the JCPOA by leading Tehran to believe that it can stonewall future investigations into its nuclear program.

Letting Iran off the hook would also embolden future violators of the Nuclear Non-Proliferation Treaty to attempt to stonewall IAEA investigations, thereby undermining global nonproliferation efforts.

To make matters worse, Iran also has thumbed its nose at U.N. Security Council resolutions calling for a halt to its ballistic missile program. Tehran has conducted two missile tests in the last two months that violate the U.N. missile ban.

In short, Tehran is actively undermining longstanding U.S. nonproliferation goals on two fronts. Yet the Obama administration has done little to push back for fear of jeopardizing its risky nuclear agreement, which it believes will enhance its foreign policy legacy.

But the administration’s complacent acquiescence to Tehran’s disturbing actions is likely to result in a dangerous and unwanted legacy: an arsenal of nuclear-tipped missiles in the hands of the world’s foremost state sponsor of terrorism.