By Jonathan Marcus
BBC diplomatic correspondent
Fresh from reacting to the Russian decision to expel four British diplomats, Britain's new Foreign Secretary David Miliband has given his first speech outlining the foreign policy challenges facing the Brown government.
David Miliband's speech was broadcast online
He made his address at the think tank Chatham House in central London.
It is hard to sum up a speech in a single word - and it was not one that Mr Miliband himself used - but "fusion" might be an appropriately modern term to describe the policies of this young, evidently bright and dynamic foreign secretary.
For Mr Miliband argued that old distinctions between foreign policy and domestic policy had collapsed.
He praised the utility of both multilateral and bilateral relationships and he stressed the need to mix instruments of soft and hard power into a new smarter way of doing the business of foreign policy.
For the highly traditional London foreign policy institute Chatham House - and for the Foreign Office itself - this was a rather unusual event.
It was jointly hosted by a global online organisation known as avaaz.org which claims to be a "million-strong global advocacy network" who carried the speech over the web.
Beyond the gimmickry and the obvious self-congratulatory smiles that everyone was being so "modern", there was a serious purpose.
Mr Miliband spoke of the need for a new diplomacy which he said could begin in the Foreign Office but would need to draw on the widest base of ideas - from think tanks to networks of concerned citizens.
There was much here that was long-standing Labour foreign policy though it was re-heated and re-stated in a succinct and coherent manner.
The foreign secretary insisted that an engaged Britain still had a major role in a world where the distribution of power had changed dramatically.
"Just as the City of London acts as the centre of the global financial market," he argued, "British cities, institutions and ideas can become the hubs for scientific cultural and political collaboration."
There was a strong multi-lateral accent to this speech. He stressed the need to reform international institutions like the United Nations.
Problems like climate change and pandemics, Mr Miliband said, required collective action on a global scale.
But he noted that bilateral relationships were also still important - none more so than that between Britain and the United States.
The US is Britain's "single-most important bilateral partnership"
The relationship with Washington he characterised as Britain's "single-most important bilateral partnership", not only because of shared values "but also because of political reality".
"The US is the world's largest economy," he went on, "engaged - whether on the Middle East peace process or climate change or international development - it has the greatest capacity to do good of any country in the world."
So no diminution of the Labour government's strong "Atlanticism" there.
Mr Miliband set out long-standing government policy on Iraq. He said that Britain would fulfil its international obligations and its obligations to the Iraqi people.
But despite all the controversy over the Iraq war, he did not shy away from the potential need for military interventions in the future.
'Force for good'
His speech also made explicit reference to the declaration at the World Summit in 2005 that the international community has a "responsibility to protect" populations from genocide, ethnic cleansing, war crimes and crimes against humanity.
This he described as "a vital new stage in the debate about the relationship between human rights and national sovereignty".
Miliband said Britain would fulfil its obligations to the Iraqi people
This idea was at the heart of former Prime Minister Tony Blair's arguments for muscular interventions abroad.
Mr Miliband nonetheless called for a new and more integrated way of combining foreign policy instruments.
"If we are to continue to be a force for good," he argued, "we need to be smart about how and when we combine the soft power of ideas and influence and the hard power of economic and military incentives and interventions."
In conclusion, the foreign secretary quoted another youthful leader, John F Kennedy, the US president of the 1960s.
He famously spoke of foreign policy based on "idealism without illusions".
Mr Miliband said he had no illusions, but that he retained the idealism "above all of a Britain that lives out its values at home and advances them abroad".