It ought to and it is British Government declared policy for the EU be successful.
“It remains overwhelmingly and compellingly in Britain’s national interest that the EU should succeed.” – Theresa May, UK prime minister, 17 January 2017
Nevertheless, the UK outside the EU may be a pre-occupation for the 27 member states. And this brings us to Brexit. The EU’s primary negotiating objective is best understood in a single word: containment – both of a United Kingdom unconstrained by membership, and of the exit contagion elsewhere introduced by Brexit.
The EU concern is that the UK wants to have its cake and eat it. For the EU, this means enjoying rights without accepting responsibilities, while having the benefits of European integration without the burdens. The institutional integrity of the EU is more important to the EU 27 than the economic value of the trading relationship with the UK.
During its 44 year EU membership, the UK has successfully secured its interests shaping the evolution of the European project – including the single market – while securing opt-outs from key parts of it. The other member states understand how ruthlessly the UK pursues its interests. One of the great ironies of the current impasse is that UK’s success in the EU creates fears of its conduct outside it.
When EU national leaders and EU institutional heads talk of “the integrity of the single market”, or “the autonomy of the union’s legal order”, as well as objecting to “cherry picking”, what they mean is that UK and the Brexit contagion must be contained, to prevent other countries from seeking to follow Britain’s example.
For the European Union, Theresa May’s requested transition period may be the best way of containing the UK.