Professor Malcolm Chalmers, Deputy Director-General of the UK’s Royal United Services Institute (RUSI) has argued that the British public’s decision to leave the European Union would necessitate a significant a shift in UK national strategy and has called for a new Strategic Defence and Security Review (SDSR).

In November 2015 the British government published its latest SDSR, setting out its national security strategy and announcing key decisions on strategic and spending priorities. Because of the political sensitivity of the subject, and the prime minister’s then-ongoing negotiations on EU reforms, it did not assess the defense and security implications of a UK exit from the EU.

Chalmers says that current plans for defense and security spending over the next decade might have to be revisited, especially if projected GDP growth fails to materialize in the aftermath of an exit vote.

“While a Brexit could lead to calls for the UK to return to a more global defense posture, there could simultaneously be countervailing pressures on the UK to redouble its commitment to European defense, in part to address concerns that an exit from the EU would risk undermining confidence in NATO, and in part because the UK’s commitment to European defense would represent one of its few bargaining chips as it entered a period of tough negotiations on the terms of its future economic engagement with its EU neighbors,” Chalmers said.