Afghan President Hamid Karzai three day visit to the UK comes as his country reaches a crucial new stage in its transition from war to democracy.
Nationwide consultations are about to begin on the draft of a new constitution for Afghanistan - part of preparations for elections which are due to take place by June next year.
Hamid Karzai is trying to secure his administration
It is a tight timetable, particularly given the insecurity that continues in various parts of the country.
The United Nations and an Afghan human rights group expressed concern earlier this week that Afghans who air their views on the new constitution could be subject to threats and intimidation.
Officials plan to reduce the opportunities for intimidation by meeting people in groups - consulting the women of a particular district as a group, for example. But they acknowledge that the process will be a challenge.
Almost everything comes down to security and to the difficulties Mr Karzai's transitional government has experienced in extending its writ across the whole country.
The government took office 18 months ago, soon after the hardline Islamic Taleban regime had been ousted after weeks of US bombing.
The US still has about 9,000 troops in Afghanistan, searching for remnants of the Taleban forces and al-Qaeda members to whom the Taleban gave shelter.
US are still searching for remnants of the Taleban forces
The Americans have launched new military operations in Afghanistan in recent weeks, anticipating that these Taleban or al-Qaeda elements would try to take advantage of the fact that the Americans were also fighting in Iraq.
But also still undermining Mr Karzai's efforts to secure his administration's hold on the country are the warlords, some of whom have sizeable private armies and engage in power struggles between themselves as well as against the attempt to impose central authority.
Mr Karzai's trip to the UK comes a few days after one important provincial leader handed over $20m in customs revenues to the central government.
This, the biggest payment of dues so far, is being seen as something of a breakthrough. The money is vitally needed to pay state employees and free up donor funding for reconstruction.
The UK Government will not be surprised if Mr Karzai repeats his long-standing request that the international force in Kabul (Isaf) be given an extended mandate to protect Afghans elsewhere in the country.
But there is now a new initiative, intended to defuse tensions in regional trouble spots and promote more visible reconstruction and development across the whole of Afghanistan.
Eight joint military and civilian Provincial Reconstruction Teams are being established. Britain will lead one of them, operating out of the northern city of Mazar-e-Sharif.
British officials say it should be in place by the end of June and will involve between 60 and 70 British troops. This is in addition to the British troops who are already part of the Isaf force in the capital.
One of the tasks of the Provincial Reconstruction Teams will be to speed up the formation of a new Afghan national army and the demobilising of the private militias, both of which are going slowly.
Another key issue on the agenda during Mr Karzai's visit will be the drugs trade in Afghanistan. Ninety per cent of the heroin in the UK originates in Afghanistan.
Britain has the role of spearheading international assistance to help the Afghan administration eliminate the growing of the opium poppy by 2013.
Worryingly, poppies are now being grown in areas where they have never been grown before.