John Bolton might want to tie Britain into the United States’ political orbit, but the relief with which Theresa May’s government greeted European support after the Skripal poisoning and Jeremy Hunt’s reflex request for Franco-German support in the Gulf suggest that the EU and its member states will still be important to British foreign policy even if Brexit happens.

But what kind of co-operation is achievable?

There are two main options: first, Britain could fall back on bilateral relations with individual countries, particularly the big five of France, Germany, Italy, Poland and Spain. This is feasible but does not bring access to collective consultations and requires the upgrading of embassies in capitals that have been steadily run down.

Second, it can attempt to negotiate special access as a “third state” to the EU’s meetings, which take place at all levels, from specialised working groups up to foreign ministers. The most important of these – because of the seniority of the officials who constitute it and the frequency of its meetings – is the political and security committee (PSC). The ideal outcome would be an associate membership of the PSC, enabling access to its agenda, papers and discussions, if not to voting rights.

At present, this seems an unlikely scenario. At best, British officials are likely to find themselves waiting in corridors outside EU meetings, hoping for privileged briefings and for the occasional invitation to present their views.

A government set on a hard Brexit might celebrate a “glad, confident morning” again with no concerns about exclusion from Europe’s foreign policy networks, preferring the dream of “global Britain”. This slogan is associated with the “Anglosphere” – the idea that the English-speaking countries and, in particular, the Five Eyes intelligence grouping of Australia, Canada, New Zealand, the UK and the United States represent a set of common values, interests and instruments sufficient to exert a powerful influence on the international system. In this case, Britain would look for further support from the 53-member Commonwealth and “strategic partnerships” with countries such as India or Japan. It would thus be exchanging its membership of a regional organisation for a geographically dispersed virtual community.

This scenario represents wishful thinking. It is true that Britain must have a global perspective and look for profits wherever they can be found. But globalism as a strategy is a different matter, for four reasons. First, in a world interconnected on so many levels, it is implausible for Britain to present itself as uniquely qualified to act as a hub. Second, a country that chooses to detach itself from its own region inevitably loses some of its attractiveness to others as both an entry point and a major player. Third, Britain is already struggling to find the resources to support foreign and defence policies. Fourth, the inability to live up to the claim to be a global player would create further reputational damage – the chaos of the past three years has already drained away much of the country’s famed “soft power”.

Facebook Twitter Pinterest Donald Trump: ‘Even if we assume that the erratic Trump presidency is an aberration, slip-streaming in US foreign policy is still unlikely to serve UK interests.’ Photograph: Jonathan Ernst/Reuters

An outward-looking identity, plus the wish to assert sovereign independence, does not translate straightforwardly into a new world role or a sustaining set of new relationships. The priorities of the other members of the Five Eyes and the Commonwealth do not focus on a close partnership with Britain.

This brings us to the tired notion of the “special relationship” with the United States. Even if we assume that the erratic Trump presidency is an aberration, slipstreaming in US foreign policy is still unlikely to serve UK interests. The asymmetry of power, differences of perspective on key issues such as Iran, climate change and China, and the contrasting dynamics of domestic politics persistently force London into choosing between uncomfortable compliance and ambivalent dissent. Neither posture fosters respect in Washington. Once out of the EU, Britain will be more exposed to US pressure, while unable to play the European leadership card in the UN security council. Its habitual claim to represent a “bridge” between the two parts of the Atlantic community will also necessarily fall by the wayside.

There are two further options for a post-EU British foreign policy, although they are more theoretical than practical: the first is that of an assertive independence, avoiding partnerships and choosing to act on an issue-by-issue basis. Leaving aside the fact that Nato already sets some limits to freedom of action, this would impose a heavy financial burden through the need to fall back on our own efforts on matters such as development aid, arms production and counter-terrorism.

The second option is renouncing international activism, doing the minimum necessary to protect the country against tangible threats, while leaving the international system to take care of itself. Hardly anyone on either the right or the left, although for different reasons, takes this line seriously. Yet the various populist movements that have emerged in Europe, from the Lega in Italy to Farageism in Britain, have moved in this direction. Leaving the EU does not change the fact that Britain will need to continue to work with its European neighbours. Geography, contrary to globalisation propaganda, has never gone away. Yet the political goods that the EU provides collectively, whether to prop up fragile states such as Bosnia or impose sanctions on rule-breakers, will not be automatically at Britain’s disposal. Any co-operation is bound to be on worse terms than now. The EU expects third states to contribute financially but does not allow them inside the room when decisions are being made.

The EU has serious problems of its own, but still performs three functions of considerable importance to the United Kingdom. First, it represents a major bloc in the international economy, with an effective common commercial policy and a currency with a growing status on the money markets. If global economic “management” has any meaning, only the large states or groups of states with the capacity to stick together will be players. The same applies for the second function, that of tackling system-wide problems such as climate change, terror networks and nuclear proliferation. Here the limits to what individual states can do are even clearer. Third, insofar as the United States, China and Russia represent potential problems for all other units in the system, regional organisations give some protection against them. The EU in particular provides cover against isolation and, on occasion, the collective weight to resist.

Foreign policy is about how we manage our political relations with the unstable and often dangerous environment of the outside world. In this respect, if we want partners with similar outlooks and interests to act as a stable support system and an influence-multiplier, our continental neighbours are the only realistic option. This has proved difficult for the British to accept because of a historical and cultural sense of exceptionalism.

It is striking how Britain trumpets its multiculturalism while being so unrelaxed about Europe. The younger generation will need to bring these two strands together in the future, for standing alone in the world is likely to prove an exposed and chilly experience.

• Christopher Hill’s latest book is The Future of British Foreign Policy