I think that very soon France and Germany will realize that they cannot support the struggling economies of much of Europe. As an economic union, the experiment will ultimately fail.
Great Britain made a mistake in joining in the integration of the European economy, and the Conservatives are beginning to recognize that.
Great Britain will continue to be an important part of NATO. Trade with Europe (and the world) will continue, economic union with Europe not a requirement.
The UK has strong trade ties with the Far East, is union with China, South Korea, Japan necessary? Of course not.