Fifty years since the signing of the Treaty of Rome, which launched the European community, world affairs correspondent Paul Reynolds looks at one of the EU's growth areas - foreign and security policy.
The European Union has quietly acquired what might be described as a standing army.
On 1 January, its concept of assigning 1500-strong multinational "battlegroups" for rapid response peacekeeping operations reached "full operational capability" when two units were declared ready for immediate assignment.
Finnish soldier of EU battlegroup
This army is not large in size, but it is large in potential. It illustrates the way the EU is gradually moving ahead in foreign and security policy.
One battlegroup is drawn from Germany, Finland and the Netherlands. The other is Franco-Belgian.
They will be on call for six months, when others will take over.
The move is part of a wider trend in EU external policy which is seeing more and more co-operation, raising the issue of how far member states want to control their own policies and how far they will be willing to act together.
After speaking to more than a dozen people around Brussels who work on or watch EU policies, I concluded that there is no chance of member states agreeing to abandon their right to go it alone in foreign policy, but equally that there is a great desire to get structures in place to make joint actions easier.
"European security policy is a growth industry," says Nicolas Kerleroux, spokesman on security policy for the Council of Ministers, the secretariat that plans and implements the meetings and decisions of the member states. "We need to streamline our ways of working."
But it goes beyond streamlining.
"Iraq was such a shock that nobody wants that to happen again," said Fraser Cameron, director of the recently founded EU/Russia Centre.
"There has been a steady 'Brusselisation' of foreign policy. More and more, external relations are decided and implemented in Brussels and people are realising that they are far more likely to achieve their ends if they go through the EU."
There is the major factor, however, that the rejection of the proposed constitution is preventing the emergence of some of the organisational changes that would take this process forward.
EU troops are on permanent stand-by for deployment
Many people in Brussels think that the way round the roadblock is to declare: "The Constitution is dead - long live the Treaty."
This means that the EU would abandon its effort to gather all its laws and procedures in one document and do what it has done before - amend previous treaties.
"It won't be called a constitution," said one senior official who did not want to be named. "That kind of gimmick was responsible for the mess we are now in."
However, an amended treaty would, it is hoped by the Brussels elite, contain most of what the constitution provided, especially on the foreign policy side.
"The main part of the institutional reforms should be ring-fenced," said British Liberal Democrat member of the European Parliament Andrew Duff, who was on the convention that drew up the constitution. "It balances power between the institutions and if you open it up, you will destroy the consensus."
However, others think that only parts will be kept. "The constitution, in its substance, is not dead. Elements will come back but it will be slimmed down," predicted Gregor Kreutzhuber of Brussels communications group GPlus Europe and a former Commission spokesman.
How much will survive, if anything, awaits first the European summit on 21-22 June and then an intergovernmental conference which some hope will take decisions by the end of this year, allowing another 12 months or so for ratification.
Incidentally, Andrew Duff told me that he had been informed by contacts in the British government that Tony Blair would remain as prime minister until the June summit in order, as Mr Duff put it, "to sign his successor Gordon Brown up to the process".
The 'Foreign Minister'
For foreign policy, an agreed treaty change would mean the creation of a "Foreign Minister", though the name is unlikely to survive as the British especially think that a "minister" implies a government.
"We all recognise that a foreign minister is one of the bits that has to be salvaged from the wreckage of the constitution," said Nicolas Kerleroux.
The idea is still generally seen in Brussels as a sound one. Even senior British officials did not discount it. The "minister" would assume the role both of the current High Representative, Javier Solana, and the Commissioner for External Affairs.
It would get rid of the extraordinarily complex system of divided responsibilities that only officials can really understand.
One such is Emma Udwin, who speaks on behalf of the Commission on external policy. An hour listening to her explanations leaves one longing for the complexities of mediaeval theology.
"The Commission supports the concept of the foreign minister," she said. "It is a young area of activity but the European Union is also ambitious. Polling shows us that people in Europe want it to play an important role and this creates the responsibility to make ourselves more effective, efficient and visible.
"We want to make peace not war and to tackle crises before they get out of hand. We are in the business of crisis management. Apart from anything else, the EU is the world's biggest aid donor with a budget of some 7bn euros and that gives it influence."
The battlegroup concept is part of that peacemaking machinery. This process has grown hugely in Brussels since some of the basic decisions on a security policy for the EU started taking shape.
The Maastricht Treaty in 1992 set up the Common Foreign and Security Policy, which it said "might in time lead to a common defence".
TREATY OF ROME
Signed 25 March 1957 at the Palazzo dei Conservatori, Rome
Original name: Treaty establishing the European Economic Community
Signatories: Belgium, France, West Germany, Italy, Luxembourg, the Netherlands
Key objectives: a common market and customs union; ever closer union among the peoples of Europe; pooling of resources to strengthen peace
Came into force on 1 January 1958
It hasn't yet and nor will it for a long time - Nato provides the real muscle - but the creation of EU structures mean that slowly the trend is emerging.
There is a permanent Military Staff in Brussels, headed by British General David Leakey. There is also a Military Commitee, led by French General Henri Bentegeat. These works at the direction of an important Political and Security Committee known by its French acronym, "Cops".
Cops has a full time ambassadorial level representative from each member state and meets twice a week at least. It provides political direction for all EU operations.
The process was given a big kick by a Blair-Chirac agreement in St Malo in 1998 for an EU "capacity for autonomous action", but this being the EU of course, matters have proceeded quite slowly. The original plan was a bit too ambitious. It was agreed in 1999 at a European summit in Helsinki that by 2003, the EU should have access to a force of 60,000. And I have not even mentioned the plan in 1950 for a European Defence Community, which came to nothing.
That proved too ambitious and it has now come down to the battlegroups, independent operational forces that can go quickly into a crisis area (usually at the request of the UN), to try to calm things down.
Political and military leaders are in practice implementing one of the key elements of the proposed constitution
The EU has carried out some 16 such operations until now, using ad hoc forces - in the Democratic Republic of Congo for example.
The battlegroup concept is designed to make this routine and structured, though the name is a bit misleading perhaps, implying more of a war-fighting role than is envisaged. Indeed, the Irish questioned its name when they applied to join the battlegroup being formed by Nordic countries (a natural fit perhaps, as the Norsemen settled in Ireland).
One interesting aspect of the battlegroups is that neutral member states find them easy to join as they are not Nato-connected and are primarily designed for peacekeeping.
There is also the European Gendarmerie Force based in Vicenza, whose participants are Italy, France, The Netherlands, Portugal and Spain. This offers a police contribution to crisis management.
Political and military leaders are in practice implementing one of the key elements of the proposed constitution - that there should be "structured co-operation" in security affairs.
Whether this will one day evolve into a "common defence" as foreseen in the Maastricht Treaty is not known. But it could be a start.