There are currently over 10,000 British Army troops deployed in Afghanistan. Several thousand others are deployed across Cyprus, the Falkland Islands, Gibraltar, the Middle East, Sierra Leone and Pakistan. Source: MoD and IISS
The Royal Navy's entire fleet is the second largest in the world in terms of combined displacement. The Navy is undergoing several major replacements: the Invincible class aircraft carriers are due to be replaced by two Queen Elizabeth-class carriers, Type 42 destroyers are being replaced by Type 45 destroyers and seven Astute-class submarines are due to replace the currently serving Trafalgar and Swiftsure-class subs. Source: MoD and IISS.
The Royal Air Force is the oldest air force in the world. It is deployed overseas in Kenya, Gibraltar, Canada, Cyprus, Norway, Ascension Island, Falkland Islands, Bosnia, Afghanistan and the United States. The UK plans to order 138 F-35B Lighting II aircraft to replace the Harrier GR7. It is also replacing the Hercules carrier aircraft with the new Airbus A400M. Source: MoD and IISS.