I will come to the way forward for Aleppo in a minute. Let me remind the House of all the ways in which the UK is trying to be of use and trying to salve the situation. Like other Members, I pay tribute to the White Helmets, who rescue men, women and children from the rubble of bomb sites. Many Members have met them. Funded partly by the UK Government, they are doing an heroic job. Of the 3,000 volunteers, 142 have been killed in the line of duty and 400 have been wounded.
Britain is at the forefront of this humanitarian response to the Syrian crisis. We have pledged £2.3 billion—our largest ever response to a single humanitarian crisis—which makes us the second largest donor after the US. We can be proud in this country of the help that we are giving to hundreds of thousands of people. Britain has done a huge amount to mobilise the international community. I pay tribute to my hon. and right hon. Friends on the Front Bench for their work in that regard. In February, we co-hosted a conference and secured pledges of more than $12 billion, which is the largest amount ever raised in a one-day conference.
Let me answer the question about whether we are taking enough refugees asked by the hon. Member for Liverpool, West Derby (Stephen Twigg). Yes, of course we should take our share, and we are doing so, but Members will agree that the overwhelming priority is to help those nearest the centres of conflict in the berm and elsewhere and to keep them as near to their communities as we can.
Let me turn to the questions that were raised by the hon. Member for Islington South and Finsbury (Emily Thornberry) and repeatedly by other Members. Many have expressed the view strongly that they want this country to go further. Others have spoken about no-fly zones, or no-bombing zones. I have every sympathy with those ideas and the motives behind them. We must work through all those types of options with our allies, especially as this House is not committed to putting boots on the ground. As my right hon. Friend the Member for New Forest West (Sir Desmond Swayne) said, we cannot commit to a no-fly zone unless we are prepared to shoot down planes or helicopters that violate that zone. We need to think very carefully about the consequences.