After surviving a siege and chemical weapons, Qusai Zakarya became an activist in his native Syria. Now in the US, he reflects on the death of "true martyr" James Foley, the American journalist who died at the hands of ISIS this week — and blasts the Obama administration for not acting in Syria.

Among the many disturbing aspects of the execution of journalist James Foley is the fact that it was part of a deliberate PR campaign. Groups like ISIS rely on hundreds of tech-savvy foreign fighters from the West to disseminate their radical vision — often with success.

The man who executed American reporter James Foley spoke with a British accent, presumably one of hundreds of British nationals that authorities think are fighting alongside members of ISIS. So why are they there, and how can they be stopped?

This isn't the setup for a joke: Last week, after the death of Robin Williams, a US Army veteran and a supporter of Islamic militant group ISIS tweeted their regrets. Soon the pair were swapping recollections of their favorite Williams movies and other pop culture trivia.

Mohamed was important in Libyan's revolution, helping to defeat and ultimately capture Muammar Gaddafi. His younger brother missed out on Libya's revolution — so he decided to make his own fame by going to Syria to fight in the violent revolution there.

Expectations are pretty low for this week's Syria peace talks in Geneva. It will the first time that government and opposition representatives actually meet since the civil war began almost three years ago. But a third major player in the conflict will be missing: the Al-Qaeda-affiliated rebel group that controls much of north-east Syria. Most of its fighters are foreign. Here's the story of one Syrian man who has been forced into exile by the very men he once helped bring into his country.