This thing has blowback written all over it.

(Reuters) – Increased use of English in videos by Islamic extremists and a rising flow of recruits from Europe to fight in Syria and on other battlegrounds is disturbing U.S. officials who fear some could return to Europe or come to the United States to plot attacks.

Only last week, a man who spoke English and Arabic and called himself Abu Ahmed al-Amriki (Arabic for ‘the American’) starred in a new video message posted on jihadist websites and produced by al Shabaab, the Islamic militant group based in Somalia.

Abu Ahmed, whose face was blurred and whose real identity is not known, called on Muslims to give up their comfortable lives in the West and head for the front lines, in places like Somalia, Mali and Afghanistan, to wage Islamic holy war, according to an account by the Long War Journal, a counterterrorism blog published by the conservative Foundation for the Defense of Democracies.

Although the fears of the West have sometimes proven overblown, this video and others highlight what senior U.S. and European security officials say is a fresh increase in English-speaking recruits, including dozens of British citizens, traveling abroad to fight – most notably to Syria.

The United States and Europe want to see Assad defeated themselves. The concern, officials said, is that many English-speaking recruits are joining the most militant, anti-Western Syrian rebel factions.

Earlier in February, a person describing himself as an “American mujahid,” or holy warrior, posted the second of two video messages touting his involvement with rebels fighting the government of Syria, according to Flashpoint Global Partners, a New York-based consulting group which monitors militant websites.