Why intelligence sharing still has a long way to go
The Paris attacks in November appeared to show that jihadists could seemingly move freely across borders while the information required to stop them did not. But improving intelligence sharing is proving a struggle.
At the 18 December EU summit, leaders promised to improve the fight against terrorism and to deal with a logjam of proposals to improve co-ordination, but it may well prove an uphill struggle.
Security and intelligence services are intrinsically secret organisations closely allied to national power and priorities. They will share their secrets - but only with those they trust.
That has worked in places like the "five eyes" alliance of English-speaking countries, but sharing data with all the other countries in the EU is a far more ambitious goal. Many security services will fear that their secrets will not always be kept when so many are involved.
Who are the 'five eyes'?
- Born out of Britain and America's tight-knit intelligence partnership in World War Two
- Out of this came what was first called BRUSA, later renamed UKUSA - a top secret intelligence-sharing alliance signed in March 1946
- Soon after the beginning of the Cold War, GCHQ and the NSA were born and the alliance formed the basis of their extremely tight co-operation during the Cold War
- The club was also expanded to include three other English-speaking countries - Canada, Australia and New Zealand and so became known as the "five eyes"
- The club is based on sharing intelligence with each other and not spying on each other
An individual name may be on a watchlist because they are under investigation but that in itself may be something the service wants to keep secret from the target and so will fear that it might leak out. Dealing with these kind of concerns and building trust takes time and real leadership.
In some countries, security services are also less well-resourced and less experienced.
France was clearly angry at the way in which Belgium appeared to have been used as an operational base for the attacks. That indicated the extent to which a country's security is tightly bound to that of its neighbours.
The Belgian government and security system has been riven by regional and local divisions that appear to have undermined its ability to operate, although they are now investing in more capabilities and providing new powers.
Different services can also operate under different rules.
Remarkably, reports from Belgium suggest they did not raid a possible hideout for one of the Paris attackers during the night because rules forbid any police raids on private homes between the hours of 21:00 and 05:00. By the time a raid occurred the next morning, there was no sign of the individual, Salah Abdeslam, who remains on the run.
The border-free Schengen zone has been put under pressure by the migration crisis, and now the security issues have added to the strain.
Poor checks on external borders mean that often residents of EU countries - including many of the Paris attackers - do not have their names run against a watchlist when they reach that border.
There is pressure from France for systematic border checks on all individuals when they reach external borders but it is not yet clear what will be implemented.
Additionally, the watchlists are often poorly maintained and do not always have all the up-to-date information from different countries because they are slow to share.
This is a major challenge when faced with EU citizens who have gone to Syria and may now be returning - in some cases to carry out violence.
New moves to improve sharing of passenger name record data for flights looks to be emerging after years of being stuck but the EU itself at the supra-national level has relatively limited capabilities.
There is an intelligence analysis centre but there is no EU-wide intelligence service and, despite some calls for one, it seems unlikely to appear any time soon.
Two divergent paths lie ahead for Europe, a recent analysis in Jane's Intelligence Review argued, "either substantially more European harmonisation, or a retrenchment to national and bilateral housekeeping".
Flow of weapons
The numbers of returnees and those seeking to go out to Syria or sympathetic to so-called Islamic State (IS) are only likely to grow and this will place an increasing strain on resources and on the need for effective prioritisation.
The leaders in December did promise to ensure systematic entry of data into the Schengen Information System and better sharing of criminal records more broadly, as well as improving the interoperability of various databases but the proof will come in whether these plans are really implemented and how quickly.
Dealing with the flow of weapons - often from Eastern Europe or from the Balkans is also going to be hard.
Guns are still relatively easy to obtain in certain countries and then drive across the border. In other cases, weapons can be legally bought in a state in which they are supposedly deactivated but can then be reactivated relatively easily by someone with some knowledge and expertise.
In the UK, there is an awareness the threat picture looks similar yet subtly different from Europe. There is no doubt that IS would like to carry out a so-called "marauding gun attack" and it may prove able to do so.
But it is thought to be harder to get hold of the kind of automatic weapons used in Paris here in the UK without coming to the authorities' attention. Being outside the Schengen zone and being an island also makes the travel back and forth harder for potential attackers - although again not impossible.
Targeting IS finances
Dealing with finances has been another area of activity post-Paris. Finance ministers talked at the UN about doing more to cut off funding for IS.
The problem is that much of this either comes from oil smuggling or from extracting revenue from the local population in Iraq and Syria and is not as susceptible to the kind of sanctions used against other groups and states in the past.
There has been increased activity against oil smuggling - including military action under an operation codenamed Tidal Wave 2 - and this may be having some impact but will do little to stop the ability to plan terrorist attacks in the short term.
Likewise, the struggle to deal with the propaganda coming out of IS and the related question of how far social media companies should go in rooting it out and also proactively providing information remains fraught.
For all those reasons, while some progress has been made post-Paris, there is still a long way to go.