As the war in Syria enters its fourth year, it's easy to lose hope. Even if there is a peace deal in the next few months - which, after the disappointments of the Geneva peace talks, seems as unlikely as ever - how will people recover, rebuild, and achieve any sort of reconciliation? How can Syria be a functioning country again?
Three years ago, a group of school-children scrawled political graffiti on a wall in the remote Syrian town of Daraa. Their subsequent arrest and torture was the spark that ignited the civil war now ravaging Syria and devastating the lives of so many of its 22 million people. This civil war is now thought to have spawned the world's worst humanitarian crisis.
Imagine the horrors of healthcare in a warzone: children having limbs amputated because of a lack of medical supplies and equipment to treat their wounds. Patients knocked out with iron bars, rather than face an operation without anaesthetic. A newborn baby dying in an incubator because of power-cuts... For millions of people inside Syria - this is the reality of their lives now.
When I visited a refugee registration centre in Lebanon recently, I heard stories of young children who have been through shocking experiences. Syrian boys and girls have fled conflict, lost their homes and watched friends and family members being killed. And now these children are facing another threat - the often hidden horror of sexual violence.
Words cannot describe the hopelessness I felt emanating from these camps, and I am not surprised that so many families decide to take the next step and leave Syria altogether. If we could just get access and reach them, it might not solve the conflict, but it would lessen the burden for families who have lost everything and ease the pressure on neighbouring countries.
It gives me no pleasure to say this: revolutions are often in vain. It is, alas, too easy to be swept up in the excitement of young protesters taking control of the streets... TV cameras blinking down from the balconies of nearby hotels give us the impression of a people in revolt, an unstoppable wave of protest, sweeping away oppression and corruption.
Right this second all around the world, millions of children are in danger. Huge numbers of children are caught up in emergencies, like conflicts in Syria and South Sudan and natural disasters like Typhoon Haiyan in the Philippines. In the Philippines 1.7million children were forced from their homes when the Typhoon swept through their communities. I saw myself how children's lives have been destroyed and how they are slowly recovering with the help of UNICEF. As a father, it was a moving experience and the memories of the children I met will stay with me for the rest of my life.