The Foreign Secretary Philip Hammond's visit to Tripoli is intended to provide visible international backing for the fledgling Government of National Accord.
He also arrived with further practical assistance; £10m-worth of aid, in part intended to combat people smuggling and terrorism.
Guide to key Libyan militias
Here then is the fundamental driver for Britain's renewed engagement with Libya (and indeed for that of other key European Union partners like France and Italy).
Libya's problems of instability are creating new ungoverned spaces in which so-called Islamic State (IS) is taking root.
The refugee crisis and trafficking of people is compounding the European Union's wider problems as refugees sometimes literally wash up on its shores.
The real question though is why now? Why has a British foreign secretary returned to Tripoli - the first visit since 2011?
And secondly what exactly are the parameters of this relationship, how far will British (and European) support go and to what extent will it have an explicitly military dimension?
The timing is the easiest to answer. The chaos in Libya has spawned two competing governments and a plethora of armed militias.
But the new UN-backed Government of National Accord, which recently set up shop in Tripoli under Fayez Sarraj, is seen as the best, albeit slim, chance of establishing some order in the country.
However, given its origins in the UN process, outside assistance carries a risk - a danger that the new government will not be seen as an outgrowth of Libyan aspirations but as something emanating from outside.
Despite the risks, the new government needs lots of help to put down roots in unpromising terrain.
Britain has been giving aid - and is going to be giving more aid. Funds will go to tackling illegal migration, smuggling and organised crime as well as counter-terrorism.
But what about practical assistance? There are persistent reports that British special forces are on the ground in Libya to counter IS.
Indeed their French counterparts have been far less successful in evading the media spotlight. Their presence was spectacularly "outed" by the French newspaper Le Monde back in February.
Special Forces are one thing but regular combat troops quite another. For some time there has been discussion about deploying a 6,000-strong European force to Libya under Italian command.
This would secure the airport in Tripoli and use this as a base to train up the Libyan military.
This proposed mission has drawn strong criticism from the Chairman of the House of Commons Foreign Affairs Committee, Crispin Blunt, who has warned that such troops could simply become targets for local militias and IS.
The British Government has been less than explicit in responding to Mr Blunt, largely taking refuge in assertions that no decisions have been taken and that no request has yet come from the new Libyan government itself.
Some kind of training may be needed and Britain is likely to play a role. An earlier effort that brought Libyan personnel to Britain ended in controversy when some of the Libyan students were found guilty of rape and other sex attacks.
Indeed their behaviour terrorised the neighbourhood and led to their prompt return to Libya.
But some kind of training assistance will be required, for the police, coastguard, and Libya's military.
The EU is likely to coordinate a significant proportion of this and it's not clear yet how much of this will take place inside Libya or in a neighbouring country - Tunisia for instance.
There could also be pressure on the Libyan government to allow international naval forces to enter Libyan territorial waters to help combat people smuggling. This could give Britain an expanded naval role.
Much will depend upon exactly what the Government of National Accord thinks it needs.
Libya's instability is now though a key threat to southern Europe and beyond.
Thus if the new government can consolidate its position it will be very difficult for the key European military players - like Britain - to refuse assistance.
After playing a leading part in the Western air campaign that helped to oust the Libyan leader Muammar Gaddafi in 2011, Britain is once again pushing to play a leading role in bringing stability to Libya's shattered society.