"The Lisbon Treaty should be viewed as a warning to the British public and Atlanticists across Europe.
On a recent trip to Washington I couldn't help but notice some of the isolationist rhetoric coming from that side of the Atlantic. Closer to home we are dealing with forces in Government that are pushing for closer European integration. Both American isolationism and European integration threaten to tear the tried-and-tested NATO alliance apart.
Consequently, the defence innovations included in the Lisbon Treaty give the UK two options. We either rely on NATO, led by the United States, to provide Europe's security as it successfully has for the last 59 years or we rely on the European Union and the European Security Defence Policy to provide Europe's security.
To me the answer is clear: the security America provides to Europe is a necessity not a luxury. It should be the aim of any British Government to ensure that NATO retains its primacy in European security.
Britain cannot have two best friends. It is time to decide.
I'm sure that Fox's approach applies in other areas. If "American isolationism" is increasing, will improving ties with Europe - via the Lisbon Treaty - test the UK's "special relationship" more generally? It's a question that MPs should keep mulling-over during the ongoing debates. Especially given that - in a recent poll - some 64 per cent of voters still regard America as Britain's "best friend".