By announcing his intention to renegotiate Britain's relations with the European Union and submit the outcome of the negotiation to a referendum, Prime Minister David Cameron has caused turmoil among his European partners.

Cameron's critics have invoked petty, ulterior motives to explain his move: With the polls showing a marked erosion of his popularity, the UK Prime Minister may seek to enhance his chances at the forthcoming elections, scheduled for 2015, by convening a referendum that 60 percent of British voters are calling for.

It would nonetheless be simplistic and misleading to regard electioneering considerations as the driving force behind the prime minister's stance; a more profound objective is at stake. To brandish the possibility of...