The children of Aleppo won't be listening to the leaders' addresses this party conference season. Nor will parents across Syria think anything said by a politician in Britain could make the slightest difference to their hellish lives and shattered country. But if we are to fulfil Theresa May's ambition for a thriving, post-Brexit 'Global Britain', the words of our leaders should - must - matter to people in countries where war is devastating lives and destroying opportunity.
After a referendum debate that brought discord and division, it is time for a grown-up conversation about Britain's place in the world. To her credit, the prime minister has made a start. She has cautioned against seeing the EU vote as a step towards global disengagement. At a time when war, terrorism and the pressures generated by globalisation are eroding democratic values, fraying the liberal economic order and challenging shared ideals of tolerance, turning inwards would be an act of folly that threatens national self-interest.
The question is whether, when they assemble in Birmingham for their conference next week, the government's new ministers are able to turn Global Britain from a slogan into a strategy. The issues to be addressed are complex and the foreign policy agenda is crowded. But focusing on children can help to cut through the complexity in areas where Britain is uniquely well-placed to make a difference.
We need to rise to three big challenges in my view.
The first is to protect children in war. The summer of 2016 has seen some of the most unspeakable violence perpetrated against children that I can remember in my lifetime.
In Yemen, an average of six children are dying every day, their homes and schools treated as military targets rather than safe spaces. Today, one million Yemeni children under five are acutely malnourished as blockades and sieges are used as weapons of war.
In Syria, children are barrel-bombed and attacked with chemical weapons - and humanitarian convoys bringing relief are destroyed. The violence in South Sudan has seen both sides using the murder and rape of children as weapons of war.
What makes these sickening acts of violence even more distressing is the total impunity enjoyed by their perpetrators. We are witnessing the collapse of a system of international humanitarian laws and human rights provisions that were framed over half-a-century following the Second World War.
Britain has a proud record of advancing humanitarianism and child rights. We should now be convening the new alliances needed to stop the war being waged against children.
Asserting global leadership in this area will require a foreign policy guided by a clear ethical standard. We are meeting that standard through the Department for International Development's humanitarian relief. Yet Britain continues to sell arms to Saudi Arabia. This is the country which, according to the UN, is responsible for almost two-thirds of civilian deaths and almost half of attacks on schools and hospitals in Yemen.
It cannot make sense that different parts of our government's policy effectively cancel each other out. That is why I hope Boris Johnson, the foreign secretary, will use the party conference to set out a strategy for investigating Saudi Arabia's compliance with international laws, which Britain has a responsibility to uphold. We must also engage with Iran and governments across the region to secure the humanitarian access needed to avert famine in Yemen.
The second challenge relates to aid. There's no shortage of criticism of the amount Britain spends on aid, but this is the vehicle through which we play our role in eradicating poverty, extending opportunities for health and education, combating corruption and supporting growth.
Children should be at the centre of our aid priorities. The past 15 years have seen extraordinary gains in many areas of their well-being. Yet almost 6 million children still die before their fifth birthday, many of them from causes - such as respiratory tract infection and diarrhea - that would be cured with a single visit to a GP in Britain. And in an increasingly knowledge-intensive global economy, more than 50 million are denied a first step on the ladder of educational opportunity in primary school.
Priti Patel, the international development secretary, has signalled that she will be looking for aid investments that deliver the highest returns. I support that approach: in a period of fiscal stress at home, getting value for money from aid is vital. Supporting the development of the health and education systems that enable kids to survive, thrive and realise their potential are among the best investments available. And Britain is uniquely well-positioned to build the global partnerships needed to deliver change.
The third challenge is about Britain's role in international cooperation. We live in an increasingly globalised, interdependent world. No country acting alone can tackle threats such as climate change, tax evasion, terrorism, and cross-border health epidemics. These are shared problems requiring multilateral solutions. As a Permanent Member of the UN Security Council, one of the largest shareholders in the International Monetary Fund and World Bank, a member of NATO, and a country with an extensive diplomatic presence, Britain has an opportunity to help create the collective solutions to global problems that are so vital to national security.
Theresa May has already demonstrated an acute awareness of the threads linking Britain to the world. Her Modern Slavery Act marked a bold attempt to ensure that the supply-chains of companies operating in the UK are not polluted by forced labour. Yet in the 21st century, modern slavery has many faces.
The 168million children forced by poverty into child labour are not free in any meaningful sense. Neither are the millions of girls forced into early marriage. As the country that led the way in abolishing slavery, Britain should be extending the principles of the Modern Slavery Act to the world stage.
The tortured debate over Europe has created a climate of uncertainty. Many governments around the world are looking for signals of intent. That is why it is so important that ministers at the Conservative conference start to underpin the 'Global Britain' approach with practical plans for action.
Today, Save the Children is publishing a set of essays that provide a vision of what an internationally-engaged, post-Brexit foreign policy might look like. There will doubtless be some people questioning why a children's charity is engaging in a dialogue about Britain's place in the world.
My answer is simple: a world in which Britain turns inwards will be immeasurably worse for children, and it will diminish us all.
Read Save the Children's 'Our today, their tomorrow' here.