In the video of Steven Sotloff's execution, ISIS threatened that its next victim would be a British aid worker, the UK confirms without naming the man, as per the BBC. Other news outlets have identified him as David Cawthorne Haines, who was abducted in Syria in early 2013. "A country like ours will not be cowed by these barbaric killers," said British PM David Cameron in a speech to Parliament today. "If they think we will weaken in the face of their threats, they are wrong." A security expert with 10 years in the military, Haines worked for civilian peacekeeping group Nonviolent Peaceforce in South Sudan and headed a mission to help refugees in Libya, the International Business Times reports. A colleague of Haines' tells NBC her "heart went into my throat" when she heard of the ISIS threat.
Officials seem divided on what should be done for Haines, urging communication but not negotiation. "What you [have] to ask yourself is whether, if succumbing to this kind of blackmail, things will turn out to be better in the end," says one official; he says it won't. UK Foreign Secretary Philip Hammond, meanwhile, insists "every possible option" will be mobilized to protect Haines, but that the video won't pressure the UK to unleash their own assault on ISIS; Cameron hasn't yet ruled that out. "We have to deal with ISIS on the basis of the wider threat that they pose to the British public as well as this individual," Hammond adds. (Read more ISIS stories.)