The UK, with France, initiated the European, today Common, Security and Defence Policy (ESDP/CSDP) in 1998–9. A strong consensus on the need to address capability shortfalls, which the UK accepted to attempt under the EU flag, however masked the lack of consensus about the extent to which the EU would also make policy and launch operations (which would require permanent planning and conduct structures).
This debate about the degree of EU autonomy vis-à-vis NATO and the US is one of the reasons why Europeans collectively have no strategic vision on the regions and scenarios for which they should assume responsibility, as the Libyan crisis demonstrated. But also on the capability side, the UK in the end never fully committed, withholding the necessary budget to allow the European Defence Agency to operate as intended and resisting moves towards military integration, such as Permanent Structured Cooperation, in favour of bilateral arrangements such as the 2010 agreement with France.
Meanwhile, however, the US came to demand that Europe take charge, autonomously, of crisis management in its own neighbourhood. British policy now seems to have struck a dead end. London has managed to slow down the CSDP. NATO has seen even fewer results in capability development, but when it comes to operations, in the absence of US leadership NATO is equally blocked by the lack of a collective European strategic vision. London, with Paris, remains the only European actor able and willing to engage in crisis management and war, but cannot mobilize many other capitals to join in. Unlike the US, the UK does not have the means to go in alone if necessary. A fundamental revision of policy is needed if the UK wants to maintain its level of influence in security and defence.