What Share America is serving up is bite-sized nuggets of video, photos and text, all optimized to be as shareable as possible on the Web. The goal is to feed content aligned with stated American values -- "democracy, freedom of expression, innovation, entrepreneurship, education, and the role of civil society," reads the site -- in the ever-hungry maw of Facebook, Twitter, Instagram and other social networks.

The group, the Active Change Foundation, a community organization in East London, began a campaign this month built around the Twitter hashtag #notinmyname, which has denounced the beheading of the British aid worker David Haines and other brutal acts committed by the radical group Islamic State.

Just as the United States has begun an aggressive air campaign against the militants, Richard A. Stengel, the under secretary of state for public diplomacy, believes the United States has no choice but to counter their propaganda with a forceful online response.

Along with its surprising military success, the Islamic State group has demonstrated a skill and sophistication with social media previously unseen in extremist groups.And just as the United States has begun an aggressive air campaign against the militants, Richard A. Stengel, the under secretary of state for public diplomacy, believes the United States has no choice but to counter their propaganda with a forceful online response.

Islamic State’s 52-second trailer“Flames of War” opens with a black-clad extremist blasting a U.S.-made tank into smoke and shrapnel, a Hollywood-style message to the U.S. and its allies about what they can expect for intervening in the Middle East again. The nation that has produced Microsoft, Apple and Google now finds itself playing catch-up on Facebook, YouTube and Twitter with an extremist group rooted in 7th Century Arabia.

Former US public diplomacy officials fear the sophisticated, social media borne propaganda of the Islamic State militant group (Isis) is outmatching American efforts at countering it.  Aimed less at Isis itself than at potential supporters, a bevy of US diplomatic and communications initiatives seek to undermine Isis’s portrayal of itself as an authentic, successful Islamic resistance.