Expeditionary warfare is built into the DNA of the British military establishment. Historically, Great Britain conducted war not by creating a great continental army, but rather by using the Royal Navy to deliver the relatively small British army to its enemies' weak points. Wellington's expedition to the Iberian Peninsula helped defeat Napoleon, and even the great formations sent to France in 1914 and 1939 were called the British Expeditionary Force.
The idea that wars should be fought at a distance has informed British military policy for centuries. To this end, the United Kingdom has historically structured its military forces with expeditionary capability in mind, even if other missions -- the British Army's commitment to the defense of West Germany, for example -- have at times competed for money and interest. That would seem to apply even more today, when for the United Kingdom, virtually every conceivable military conflict is an expeditionary war.
However, the defense cuts outlined in the Strategic Defense and Security Review (.pdf) threaten to undermine Britain's ability to undertake expeditionary operations. For the first time in centuries, the United Kingdom will effectively lose the ability to conduct unilateral expeditionary war.