"The state of relations between Britain and the EU are such to justify some speculation: what would the EU's foreign and security policy look like without London? Is Britain's global vision, and its worldwide network, knowledge and understanding of the world, so important to the EU?
After all, the engine of integration has always been the Franco-German axis. France too has a century-old global foreign policy backed by a worldwide network, Germany has a global economic presence and weight, a number of Nordic countries have a strong international tradition of peace-making and keeping, and countries like Spain, Italy and Poland have a strong interest in pursuing a common European policy in the EU's neighbourhoods to the South and to the East, as well as long-standing policies towards important parts of the world.
Perhaps the EU can have a foreign policy without Britain. A British exit could even stimulate more integration in EU external policy, even without abandoning the intergovernmentalism of the Common Foreign and Security Policy (CFSP) proper. What would the issues currently on the table of European decision-makers look like without Britain playing a role?
Britain has always considered its 'special relationship' with the US as alternative or different to its relations with the rest of Europe, forgetting that Washington has been one of the EU's strongest supporters from its very early days and not listening to some loud and clear messages, such as US Assistant Secretary of State for European and Eurasian Affairs Philip Gordon's recent speech.
By leaving the EU, London would make life more complicated for the US rather than for the EU. Washington would lose a key European interlocutor and have to work harder to charm Paris, Berlin and Brussels to build common positions in areas of common interest. What London has not understood is that in the US, there is no doubt that Europe is the important partner.
This said, would the EU minus Britain be able to live up to the role the US would like it to play? It is already struggling to do so today. Without London, on Israel and the Middle East the EU could become even more polarised between countries with a stronger pro-Arab tradition and large communities of Arab origin, and those more sensitive to Israel's positions, with repercussions for the EU's approach towards the Arab world. How the US may fit in this cleavage is a rather worrying question mark.
In security and defence, London would be quite happy to continue with ad hoc and bi- or multilateral cooperation between European states, mostly France, limiting the potential for spill-over to further integration. Here, the only hope for the rest of Europe to make Common Security and Defence Policy (CSDP) relevant would be a push for further integration starting from the defence sector. But the recent failed merger between British-controlled BAE Systems and Franco-German EADS last October, due to German resistance, illustrated how far apart Paris and Berlin are in thinking about long-term industrial and defence strategy, just a few months after they split over the NATO intervention in Libya. In security and defence, none of the other member states can replace Britain's military and strategic weight.
The Libyan episode showed that Paris and Berlin are not in unison when it comes to issues relating to war and peace – the core dilemma of international relations.
But there are other areas in which the two do see eye to eye. Both are far more comfortable than Britain in their relationships with Putin's Russia.
The EU could forget about improving relations with Ankara. Without Britain, Paris and Berlin may feel they could do away with the farce of Turkey's accession, which neither really wants. Enlargement beyond Croatia may also suffer a blow without one of the countries most committed to the Balkans and to further EU expansion. There might be temptations to create a second or third-tier Europe to include Britain, Turkey, the European Economic Area, and the Balkans.
These examples are perhaps biased: they represent crucial areas in which France and Germany diverge or converge dramatically. The EU is far more diverse and includes member states which, even if smaller in size, do influence and shape foreign policy in important ways, as Swedish-Polish cooperation shows. And foreign policy is not driven solely by member states. The EU is leading other important international policies too, such as the fight against climate change or international trade deals.
But a foreign policy dominated by the Franco-German axis would still appear rather grim and insular. How would the other member states see EU foreign policy without Britain? Would they prefer a policy which is 'bad' but common, or would they fall back on fragmented positions? If the euro zone were to move towards greater integration, it is possible that this will affect its external interests and priorities, spilling over into foreign policy. As things stand today in terms of internal political balance, this would mean the dominance of France and Germany.
The other EU countries that are most active (and often successful) in shaping EU foreign policy are Sweden and Poland, and they are not in the euro zone (yet). They would certainly try to influence EU foreign policy without Britain, and would probably be able to drum up the support of like-minded countries which are not keen on Franco-German dominance. So there would be a push towards more integration in the foreign policy field: the need to have more global weight will force the euro zone towards more common international policies, including traditional diplomacy and security policy.
Where would this scenario leave Britain? London does see the added value of EU foreign policy; it just does so pragmatically. It cherry picks the areas in which cooperation with the other EU member states, institutions and resources is seen as useful to the 'British national interest'. It prefers the EU to deal with niche areas, but has been very supportive of efforts to coordinate sanctions against Syria or of the talks with Iran, for example.
So even if Britain were to leave the European Union, it would want to cooperate with the EU on select issues (of its choice, of course). But if things do change on the continent and move towards more integrated international policies it would be harder for Britain to influence and shape such polices.
Abstract speculation has led in many directions but to one symmetrical picture: a grim and insular foreign policy for the EU, and a damp and dismal foreign policy for Britain."
Rosa Balfour is a senior policy analyst at the European Policy Centre, where she heads the Europe in the World programme.