Syria has been enigmatic about its nuclear program ever since Israeli air force jets destroyed a reactor in the middle of the night in September 2007. Mystery surrounded the incident. Even the U.S. took weeks to confirm that what had been hit was indeed a facility, based on a North Korean design, which could have produced bomb material. By the time International Atomic Energy Agency (IAEA) inspectors arrived in Syria in June 2008, the Dair Alzour site had been completely cleared, though some traces of uranium still were found.

The site, also known as al-Kibar, has not remained vacant. While President Bashar al-Assad prohibited any more IAEA visits to Syria, asserting that they would violate his country’s sovereignty, Dair Alzour has been rebuilt and at least one other nuclear site is operating near Damascus.

As a signatory of the Nuclear Non-Proliferation Treaty, Syria is obligated to cooperate fully with the IAEA. Obstinacy earned Syria top billing, together with Iran, at the IAEA board meeting this week. IAEA Director-General Yukiya Amano, in sharp contrast to his predecessor, Mohammed El Baradei, has openly challenged Tehran and Damascus to be forthcoming about their nuclear programs.

In the case of Syria, there is genuine concern that President al-Assad wants Syria to be the first Arab nation to develop a nuclear weapon, and he is not allowing the memory of one Israeli attack or the constant queries of world powers to get in the way.

The United States shares Amano’s growing impatience. Glyn Davies, U.S. ambassador to the IAEA, accused Syria of “deliberate efforts to conceal the full extent and scope of what we strongly believe were, and may still be, clandestine nuclear activities,” and threatened Syria with isolation.

What are the options?

The IAEA can continue to try to work with the Assad regime, and hope it provides the transparency that has been missing in dealings with Iran on its nuclear program. On the eve of the Vienna meeting, in an effort to stave off criticism or stronger action, Syria did offer to allow IAEA inspectors to visit, but only to see a site in Homs.

But that’s not the place that the IAEA wants to visit in order to gain the information needed for a full assessment of the Syrian program. Accepting this offer would compromise the authority of the international nuclear watchdog and excuse Syria.

Or, Syria can be referred to the UN Security Council, which already has adopted four resolutions against Iran. True, Iran has ignored those actions, as well as the series of additional sanctions imposed by the U.S., EU and other countries. As Amano stated, the IAEA cannot “confirm that all nuclear material in Iran is in peaceful activities” because Tehran has refused to provide information requested, prevented access to nuclear sites, and barred IAEA inspectors from entering the country.

A third option, isolating Syria globally, as Ambassador Davies suggests, could backfire. After all, isolating North Korea did not stop it from banning IAEA inspectors, withdrawing from the NPT, and testing nuclear weapons.

Not easy choices. Still, there are good reasons to suspect the worst about the Assad regime’s intentions. The al-Assad family, Bashar and his late father Hafez, have ruled Syria repressively for more than 40 years.

Human rights abuses and denial of free expression are the norm. Popular uprisings like those occurring across the Arab world are not likely to emerge in Syria soon.

Moreover, Syria hosts Hezbollah, Hamas and other major terrorist organizations. And, the al-Assad regime has long favored interfering in the internal affairs of Lebanon. Together with Iran, Syria helped Hezbollah force a bloodless coup, bringing down the government of Saad Hariri.

In sum, Syria is one of the last countries on earth that should be allowed to attain nuclear capability. Going nuclear will only embolden the rigidity of the regime’s rule and threats to neighbors.

The IAEA’s Amano recently told The Washington Post that he is determined to be “the guardian of nonproliferation,” which is precisely the purpose of the NPT, adopted by the UN in 1970, and renewed last year. Both North Korea and Iran, by their actions, have openly challenged the efficacy of this key international treaty, and Syria may be inclined to emulate its two allies.

The U.S. should reassert leadership in coordinating international efforts to convince Damascus to desist. It would be a test case for President Obama’s pledge in 2009 to achieve “a world without nuclear weapons.”

Kenneth Bandler is the American Jewish Committee’s director of communications.