Sir Jeremy Greenstock, a former ambassador to the UN and the UK's special representative for Iraq until 2004, has told ITV news Britain should support the US military intervention in Iraq in a limited way.
He said airstrikes were likely to be effective in driving back Islamic State fighters who're threatening the Kurdish regional capital, Irbil - and have driven tens of thousands to take refuge on Mount Sinjar.
Sir Jeremy said: "I think airpower can be quite effective in limiting the range that these people can move on the ground.
It's very exposed territory, there is very little cover so they can be caught on roads, they can be caught with their artillery pieces, they can be stopped. But the Kurds themselves don't have the equipment to do that.
I think we should be thinking in terms of supporting the American military action, helping with the humanitarian action, perhaps supplying some helicopter activity which would need its own defensive arrangements but going no further than that.
Kurdish Peshmerga fighters have emerged victorious in the battle for Mosul Dam, but the question is - what will their next move be?
An ITV News team at Mosul Dam was with victorious Kurdish Peshmerga fighters at the complex earlier today.
ITV News joined a Kurdish unit fighting Islamist militants near Irbil and found them using tanks from the 1950s and short on ammunition.