WASHINGTON -- President Barack Obama and Republican challenger Mitt Romney traded barbs on foreign policy Monday night, dueling over everything from military spending to Middle East events to how best to stop Iran from acquiring a nuclear weapon.

In the last of three high-stakes presidential debates, not everything they said at Lynn University in the Florida beach city of Boca Raton squared with reality. Here’s a fact check of some of what they said:

SYRIA:

Obama said he was confident that (Bashar) “Assad’s days are numbered.” However, there’s no evidence to support that the Syrian leader’s fall is imminent, and the administration has repeated that line for several months now with no significant military progress by the rebels.

While it’s true that the rebels have managed to capture sizable parts of the country, they’ve struggled to hold those territories against the better-armed regime forces, and experts agree that there’s no way the rebels can win militarily without either a crucial infusion of heavy weapons or direct foreign military intervention. By contrast, 19 months into the uprising, Assad is still in power, his inner circle is largely intact, and his military is still strong enough to call up reinforcements. Without an assassination or some form of outside military help for the rebels, experts say, Assad could hang on for many more months or even years.

Romney blasted Obama for failing to take “a leading role” in organizing the Syrian political opposition and uniting the “disparate” rebel factions under a single opposition banner.

The United States, along with France and other Western allies, has tried for more than a year to pressure Syrian opposition forces to form a government-in-waiting and streamline the rebel forces. In addition, the U.S. government has allocated more than $130 million in nonlethal and humanitarian aid to Syrian dissidents to spur them to organize.

However, the Syrian dissidents themselves are deeply divided and openly admit that their own ideological and religious differences have prevented the formation of a potential transitional government, as the Libyans managed to create before the fall of Moammar Gadhafi.

LIBYA:

President Obama’s notion that U.S. interlocutors only worked with relatively moderate opposition forces during the Libyan uprising is misleading. The United States backed the National Transitional Council, a self-appointed group of exiles and dissidents that included conservative Islamists as well as secularists.

Meanwhile, the rebels who fought Gadhafi’s forces were a hodge-podge of military defectors, civilians and former jihadists – just like in Syria today. The United States, the lead partner in the NATO alliance, supported those rebels militarily. Many of the most seasoned fighters were veteran jihadists, including some of who’d fought U.S. forces in Iraq or Afghanistan. When the U.S. consulate in Benghazi was attacked in September, the attackers used rocket-propelled grenades that may have come from the arsenal left behind in Gadhafi’s collapse.

IRAN:

Romney was misleading in asserting – as he has previously – that Iran is “four years closer” to having a nuclear weapon. The greatest hurdle to developing nuclear weapons is enriching uranium, and Iran crossed that line almost six years ago, when technicians began feeding uranium hexafluoride gas into high-speed centrifuges at the country’s main enrichment facility at Natanz. He was correct in noting that work has continued. Iran has installed thousands of centrifuges in Natanz, brought on line a second facility buried below a mountain near the holy city of Qom and built up stocks of 3.5 percent and near 20 percent low-enriched uranium that Iran says it wants for fuel for nuclear power reactors and a research reactor that produces medical isotopes. Those stocks can be further enriched to highly enriched uranium, or HEU, for a weapon using the same centrifuges. But if Iran were to move to produce HEU, it would almost certainly be immediately detected by U.N. inspectors and monitoring devices, putting Iran’s facilities at risk of U.S. airstrikes, most experts agree.