UK Prime Minister David Cameron says Britain will not give in to militants in Iraq and Syria, despite threats from them to behead a British hostage.
It follows the apparent beheading of US journalist Steven Sotloff by Islamic State militants who threaten to kill a British hostage next.
The latest IS video comes ahead of a major summit in the UK of leaders of members of the NATO military alliance.
ANd it again appears to involve a British murderer.
But the UK is still resisting calls from some quarters to carry out air strikes on Islamic State positions in Syria and Iraq.
Olly Barratt will be at that summit and has this report.
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Another video from IS and again, a British voice.
Now, also, a threat to kill a British hostage next.
Focusing British minds even further - on what to do about Islamic State militants in Syria and Iraq.
David Cameron says Britain won't be intimidated.
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But he isn't committing to any new course of action as a result of the latest video.
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But Defence Secretary Philip Hammond isn't ruling out military action at some point.
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But the British hosts now go into a NATO summit with Syria, Iraq and Ukraine, needing attention.
Only a matter of months ago this was a summit at which it wasn't entirely clear what NATO members would talk about, with missions in Iraq and Afghanistan ending or at an end.
That's all changed.
And one of the main issues is how much are members willing and able to contribute in terms of resources.
The UK does hit its NATO target for defence spending, as does the US, but most members don't - surprised by the UKraine conflict at a time when many thought they could scale back military expenditure.
DR. JAMES D. BOYS, US POLITICAL HISTORIAN, says until the Ukraine crisis emerged, it would have been a hard sell to voters.
"In a time of austerity, how do you justify that, when there is no open conflict, it's all very well and good to say now in hindsight well maybe we should have been spending more on defence…
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It's thought NATO will agree a new 4000 strong rapid response force for eastern europe to show Vladimir Putin it still means business.
When it comes to Iraq, NATO hasn't yet received any specific request for assistance.
And NATO secretary general anders fogh rasmussen hints that he believes the Islamic State militant group wouldn't have succeeded in taking large parts of the country - if his organisation had been able to stay longer.
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NATO officials are suggesting this could be the most important summit in its history.
Iraq and Syria will be discussed by leaders.
But crucially they want to demonstrate to Vladimir Putin that the military alliance still has teeth.
OB, London