Western countries are making concerted efforts to bar foreigners from joining militants in Syria and Iraq. However, some volunteers manage to reach the battle line and get into terrorist operations.

An official from the US intelligence says that at least 6,000 of those 34,000 foreign fighters are Westerners. These numbers show a small increase since October 2015.

Several factors account for successful recruitment of foreigners. Young people are drawn to jihad, or Islamic holy war. There is also evidence that the jihad message continues to appeal to European young men and women. Most foreign fighters arrived in the combat zone after the Islamic State had seized Mosul in June 2014.

"As long as people are willing to go there, they can get there. We overestimated our ability to disrupt moves of militants," noted Patrick Skinner, a security expert at the Soufan Group. US Defense officials have got hard evidence that the Islamic State is brainwashing people into joining its army. The terrorist group accepts newcomers on a regular basis keeping the overall personnel at 20,000-30,000 soldiers.

Unfortunately, more and more foreigners, including Americans, are ready to deploy in the combat zone. They are facing a problem of how to get there. That is why all departing people have to go through a tough control.

US anti-terrorist agencies express fears that Russia’s involvement in the conflict in support of Syria’s President Bashar Assad could inspire even more people to join IGIL fighters.