The approximately 5,000 Arab foreign insurgents fighting in rebel Syrian ranks are a collective “ticking bomb for their countries of origin,” a new study by Israeli security experts said Tuesday.Many of the volunteers pose a risk when they return, due to the likelihood of them setting up local jihad nodes, joining domestic networks, or forming local branches of transnational Syria-based terror networks, the authors said.The study was released by the Tel Aviv-based Meir Amit Intelligence and Terrorism Information Center, which was founded a decade ago. It is the latest in a series of in-depth studies published on the center’s website examining the actors involved in the Syrian conflict.When in Syria, foreign Arab fighters mostly join the al-Qaida-affiliated Al-Nusra Front and its jihadi rival, the Islamic State of Iraq and Greater Syria (ISIS), the study found.Countries particularly at risk are Saudi Arabia, Egypt, Jordan, Libya, Iraq and the Persian Gulf states, it said, noting that the fighters acquired “operational experience and combat skills, are inculcated with the ideology of jihad and radical Islam, and form a network of contacts with Salafist jihadi organizations and operatives throughout the Arab-Muslim world.”Upon their return, fighters are likely to join local jihadi networks or establish new ones for terrorism and subversion. “In our assessment, the networks will operate in coordination with, or be directed by, the Al-Nusra Front and ISIS, through contacts made in Syria,” said the authors.Although the phenomenon is still nascent, the future is filled with security risks, they added.Some initial warning signs have appeared in Egypt, where Syria war veterans have been detained for involvement in terrorist activities against the Egyptian regime, or were killed in attacks by Egypt-based terror group Ansar Bayt al-Maqdis.Saudi authorities exposed a terror network operating in Saudi Arabia earlier this month.In Jordan, “ISIS encouraged demonstrations and riots in the southern city of Ma’an, a hotbed of anti-regime subversive activity,” the study said.Two Israeli Arab volunteers whom Syrian jihadis asked to carry out terror attacks in Israel were arrested by security agencies prior to carrying out their attack.Reuven Erlich, who heads the Intelligence and Terrorism Information Center, told The Jerusalem Post that “in Syria, al-Qaida built a major infrastructure, and this is where it is the strongest. This is a plague that is not staying in Syria, but moving outside, to all of the Arab world, the West, and it could get to Israel.”He said Arab countries had begun responding to the threat, employing measures such as legislation to ban their citizens from traveling to fight, and surveillance of those returning from Syrian battlegrounds.The more Syria veterans return to Arab states, he warned, the more global jihad networks are likely to grow in the Middle East.“This is only the start,” Erlich said. “Today, the infrastructure of al-Qaida is no longer in Afghanistan-Pakistan. The new global terrorism center is in Syria. It has completely different characteristics. And it is here, right under our nose. The growth of terrorism networks based in Syria is much faster than those that sprung out of Afghanistan.”The center’s report said that the 5,000 Arab volunteers form the majority of the 7,000-8,000 non-Syrian combatants fighting against the Assad regime.Only a minority of Arab fighters have joined the Free Syrian Army and other non-jihadi rebel organizations.Volunteers are often driven by ideology, religious-sectarian motives, sympathy for the Syrian people, and hostility to the Assad regime, as well as a desire for adventure, the report continued.Many of them arrive with little training or combat experience.These volunteers include “a hard core of Salafi-jihadi, al-Qaida and global jihad operatives, some of them veterans of the fighting in Afghanistan, Iraq, Libya, and other Islamic combat zones,” the report said.“Most of the Arab foreign fighters come from towns and villages, with only a few coming from the main cities.”According to the authors’ assessment, “the Arab foreign fighters form the backbone of the forces fighting in the ranks of the Al-Nusra Front and the ISIS. They also have a high casualty rate and many are killed.”Saudis make up a high number of suicide bombers, the authors added.They said countries that sent many volunteers were ones that had experienced upheaval, such as Tunisia, Libya and Egypt. Pro-Western states like Saudi Arabia and Jordan, which have preserved their stability, have recently launched efforts to stop the flow of their nationals to Syria.Initially these governments saw the volunteers as combatants against Iran and Shi’ite Islam, but over the last year, “the dangers of terrorism and subversion from Syrian veterans became apparent, as they returned to their countries of origin,” the report said. That prompted some of the Arab regimes to take preventative action.Additionally, the study said, a number of localized Salafi- jihadi networks have sent volunteers to Syria, including the Tunisian Ansar al-Sharia, the Egyptian Ansar al-Sharia and Ansar Bayt al-Maqdis, the Bahraini Jamiyya al-Asala al-Islamiya, and the Lebanese Fatah al-Islam. Other groups include Jaish al-Umman, based in Gaza, and Gazan jihadi organizations.