Thousands of foreign terrorists traveled to Syria over the past several months to wage jihad, or holy war, in what U.S. officials say is fast becoming a new international terror training ground.
Most of the foreign terrorists are fighting for the al Qaeda-linked group the al-Nusra Front and are coming from around the world, mainly from Saudi Arabia, Iraq, Libya, and Tunisia, by crossing the Syrian border with Turkey. The al-Nusra Front is the most well organized and ideologically motivated armed opposition group after the secular Free Syrian Army.
"The Syrian opposition is benefiting from a steady flow of foreign fighters who seem to be joining a variety of Islamist-oriented brigades or, on a smaller scale, starting up nationality-based units," said one U.S. official familiar with internal reports on the region.
Bruce Riedel, a former CIA official and former staff member of the White House National Security Council, added: "Syria is the new epicenter for the global jihad with would be ‘martyrs' arriving from across the Islamic world to fight Assad. They are getting experience in the terror arts they will bring home."
Word of the growing foreign terrorist presence comes as a gruesome video surfaced over the past weekend showing Syrian rebels beheading three Christians, including a Catholic priest, in a public execution widely circulated on the Internet.
The Obama administration announced last month that it will begin sending arms to secular rebel groups fighting under the Free Syrian Army banner. Critics have warned that the covert U.S. support could end up bolstering al Qaeda forces in the region.
"The balance of power within the Syrian opposition between responsible forces and terrorists is already murky at best," John Bolton, former U.S. Ambassador to the United Nations, told the Washington Free Beacon.
"If even more al Qaeda supporters are moving in, it raises the risks of supplying weapons even to ‘friendly’ opposition forces even higher," he said.
The number of "martyrdom announcements" by jihadists in Syria indicates the influx of foreigners is increasing, said officials who spoke on condition of anonymity.
Officials familiar with reports of the foreign fighters said many of the jihadists are Sunni Muslims initially drawn to the conflict to help the Syrian people and oppose Shiites.
However, one official said the fact that most are joining al-Nusra Front and another Chechen terrorist group are troubling signs since it is believed the foreign fighters will become "hardened jihadists" through the experience.
The increase in foreign terrorists began in December and is continuing. U.S. officials estimate many as 6,000 foreign terrorists are now fighting in Syria and the large numbers have increased fears among security officials that the terrorists will use their experience to spread terror to their home countries.
More than 600 Islamist foreigners were reported killed in fighting in Syria since the beginning of the year.
Al-Nusra and the Chechen-led Jaysh Al-Muhajirin wal Ansar rebel group, which collaborates with al-Nusra, are the main jihadist groups that have helped funnel foreign terrorists into the conflict.
According to the officials, Syria is becoming a new terrorist training ground as most of the foreign fighters joining the conflict have little or no jihadist experience.
For example, the martyrdom statements of the dead jihadists revealed that among the more than 600 dead, fewer than 20 were experienced fighters from Afghanistan, Libya, or elsewhere.
The easy access to the Syrian conflict is viewed as a main factor in the increase of foreign fighters.
It has become relatively easy for terrorists to reach the Islamist rebels through the Turkish-Syrian border, the officials said.
Chechen terrorists have set up an Internet site that helps fighters reach the Jaysh Al-Muhajirin wal Ansar group by traveling to Turkey and then crossing easily into Syria.
According to London’s Arabic-language newspaper Al-Sharq al-Awsat, Libyan terrorist leader Abu-Yahya has said there is an easy travel route for Tunisian and Libyan fighters, who are being trained in Libya for jihad in Syria, to be smuggled into Syria with the help of militant groups.
The conflict in Syria also has pitted Muslims against each other. Many Sunni militants initially traveled to Syria to wage jihad against Shiites, like the Iranian-backed Hezbollah terrorist group that is supporting the Assad regime.
The Syrian conflict also has exposed a rift within al Qaeda. The Iraqi al Qaeda group known as the Islamic State of Iraq merged with Al-Nusra Front in March to create the Islamist State of Iraq and the Levant. However, al Qaeda leader Aymen al Zawahiri announced that the merger was not valid.
Meanwhile, weapons continue flowing into the Syrian conflict for both rebels and the Assad regime.
Reports from the region indicate governments in Saudi Arabia, Qatar, and Turkey are the most active supplying an array of missiles, including both anti-aircraft and anti-tank missiles to Islamist groups. France has supplied anti-aircraft missiles and other weapons to Free Syrian Army rebels.
Of particular concern are reports that the Islamist rebels are receiving significant numbers of Russian-made SA-7 anti-aircraft missiles. The shoulder-fired missiles are considered ideal terrorist weapons that could be used against commercial airliners.
Reports from northern Syria indicate Chechen jihadists there are equipped with more advanced SA-16 surface-to-air missiles.
Russia and Iran have been arming the Assad regime’s forces. News reports from Asia stated in early June that North Korea’s military had sent about a dozen troops to aid the Assad regime as advisers.
Estimating numbers of foreign terrorists in Syria is difficult. But officials said most of the foreigners appear to be from Libya, with reportedly some several hundred Libyan jihadists; Saudi Arabia with at least 330; several hundred Egyptian Islamists and around 300 Iraqis. Jordan’s jihadist contingent in Syria is said to number more than 500.
Other nationalities observed engaged in Syria jihad include Kuwaitis, Lebanese, Palestinians, Qataris, Algerians, and Moroccans.
Non-Arab jihadists include smaller numbers of terrorists from China, Australia, Britain, Denmark, France, Germany, Netherlands, Sweden, Canada, Russia, Azerbaijan, Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, Austria, Belgium, and Bosnia. It could not be learned if any American jihadists are in Syria.
Analyst said one of the main dangers from the influx of foreign fighters is that the fighters will use their jihadist experience to continuing waging jihad around the world.
"Not everyone who has joined the Syrian rebels is al Qaeda, and only a small number may ever become involved in terrorism after returning to Europe," said Aaron Y. Zelin of Washington Institute for Near East Policy in a recent paper.
"That said, it would be wrong to conclude that individuals who have trained and fought in Syria pose no potential threat. Numerous studies show that individuals with foreign training and/or fighting experience have featured prominently in European based terrorist plots."
Other studies have shown that foreign-trained terrorists "are far more lethal, dangerous and sophisticated than purely domestic cells," Zelin stated, noting that the Syrian conflict could produce a new generation of terrorists like the conflicts in Iraq in the 2000s, Bosnia in the 1990s, and Afghanistan in the 1980s.