What happens over there may just make a difference to what goes on over here. BBC London’s Special Correspondent Kurt Barling spent part of this week adding to his working definition of what makes a world city.
Always in search of an explanation for the things that make our city tick I took a call early last Saturday morning from the Algerian embassy in London.
The day before, the police had detained several Algerian men in London and Manchester as they are deemed to be a threat to national security.
There will now be, no doubt, much legal debate about whether they can be deported to a country where Amnesty International says the security services routinely torture suspects. A country which has until recently been, to its great cost, at war with itself.
The phone call was to tell me that, coincidently, one of the most important men in Algeria was paying a flying visit to London and would I be interested in talking to him.
Abdelaziz Ben Khadem is a special adviser to the Algerian president and the general secretary of the National Liberation Front (FLN) which steered Algeria to independence from France in 1962.
He was busy canvassing for the referendum that is to take place in Algeria on 29th September.
The vote is for a charter for peace and reconciliation not unlike that which brokered the transition away from apartheid South Africa.
From his perspective if the referendum can get Algeria back on a path to prosperity it will bring direct benefits to a city like London.
Firstly, it will attract émigrés home and secondly it will extinguish one of the motivations for those who engage in terrorism.
Talking to Algerians about home brings a mixture of nostalgia and anxiety: Nostalgia for the good old times and anxiety about whether it’s safe to go back or even if they want to go back at all.
You might call it the asylum seekers burden. Once you’ve found a safe haven and a comfortable lifestyle, why give it up.
The Algerian League in Britain (ALB) says that many people from within that community are considering whether it’s getting close to the time when they could return to their homeland.
I can only recall one mass exodus from these shores in recent times and that was the Eritrean community who in overwhelming numbers packed their bags and headed for home immediately after celebrating independence in 1993. It seems to me Algerians appear similarly passionate about rebuilding their country.
But the ALB says there are more pressing and distracting concerns which is making London feel less safe. Algerians are predominantly Muslim and they feel in the current anti-terror climate the actions of a militant minority who came to the country in the late 1990s are threatening to isolate them from the mainstream British life.
Despite the fact that we’re talking about law abiding participants in London life, the arrests of seven of their compatriots last week has simply heightened their collective sense of vulnerability.
They know only too well that the likes of Omar Bakri Mohammed (now no longer welcome in Britain and residing somewhere in Lebanon) and Abu Qatada found many young Algerian men willing to follow their radical teachings.
Finsbury Park mosque in north London became well known as a place where new migrants from the Maghreb could come and find a sympathetic ear, some food and a temporary roof over their head.
Filming secretly there in 2000 for a television documentary, we discovered it was also a place where there was a vibrant trade in false passports, forged credit cards and a heady mix of Jihad (holy war) by any means necessary.
Many of these young men had been summarily expelled from France, who at the time took a more direct approach to dealing with individuals who posed a threat to national security.
Few video stores in London stocked foreign language films at the time. Not so Finsbury Park mosque which was stacked full of calls to Jihad and discourses on radical Islam in French and Arabic.
About this time the Algerian security services were very keen to find out what was going on in the mosque. In collaboration with the French intelligence services they monitored the activities of the congregation.
I have it from a good source that the former French Minister of the Interior, Jean-Pierre Chevenement could not sleep a wink on Thursdays.
He and his Algerian counterparts would be on tenterhooks to see what fatwa would be issued from the mosque on Fridays. It’s alleged that what was said there had a direct impact on terrorist actions on the streets of Algiers.
It acted as a kind of overseas operations centre for the GIA - the radical Muslim group that was responsible for countless massacres in Algeria.
One Algerian radical, Mohamed Meguerba, who frequented the mosque, left London to go to an al-Qaeda training camp in Afghanistan.
He is now in an Algerian prison, imprisoned for trying to enter the country without papers in 2002 and trying to hook up with a militant group called the Daawa Salafia.
It was he who implicated the seven Algerians in the alleged Wood Green Ricin plot, allegedly after being tortured.
All those men were acquitted of involvement in the alleged plot at an Old Bailey trial earlier this year but they are among those re-arrested last Friday.
This is where London’s international connections become critical. Kamel Bourghass who was also part of the alleged Ricin plot was convicted of murdering Detective Constable Stephen Oake.
He stabbed DC Oake during a raid on premises in Manchester whilst police were investigating the ricin allegations.
Bourghass had lived in the Wood Green flat that had already been raided by police searching for evidence of ricin and fled to Manchester. He was an associate - yes you guessed it - of Meguerba.
Here comes the punch line. This story was used by both the Tony Blair in Parliament and Colin Powell before the United Nations Assembly to make the case for a war in Iraq.
If ever a stone caused ripples in a pond, then the crisis in Algeria made one hell of a splash in the pond of international affairs.
Of course even if Algeria’s crisis is in check and moving swiftly towards a resolution, the idea that sparked it has caught hold here amongst some very impressionable young Muslim men whose only link with Algeria is through the idea of how to conduct Jihad.
Men like the 7 July London bombers shown carrying out a practice run in the CCTV footage made public by the Metropolitan Police earlier this week.
One thing about reporting for TV is that you get to look at the pictures a lot more than the audience.
I watched those fleeting snatches of the three men over and over again. What struck me about those CCTV pictures at Luton station and King’s Cross is that those young men looked relaxed.
They looked confident and they looked like they had self-belief.
I heard it said once that the power of an idea lies is in its ability to alter people’s lives – for good or for bad.
If that’s the case then it seems it’s on the ideas front where we need to work the hardest at the moment.
We need to convince these young men that our idea is better than theirs.
Hopefully that is precisely what Home Secretary Charles Clarke’s recently announced Commission is going to help us try and achieve.
This brings me back to the Special Adviser to the President and that Saturday morning phone call.
He was here to encourage the idea of peace and reconciliation amongst his own people. It is his considered view that the bloodshed in his country has not gained very much for his countrymen.
He told me this is the most important moment for Algeria since General Charles de Gaulle said the French wanted to leave.
But he also had a more subtle message for us over here. If we are to defeat terrorism and prosper we cannot afford to ignore the calamitous affairs of other nations.
He reckons the lesson of Algeria is if you ignore a calamity in someone else’s country, it eventually becomes a calamity over here - as we now know only to well in this city.
It almost makes you feel like voting in Algeria.