Exchange officers usually serve in similar roles to those that their career path would take them were they to remain in the armed forces of their home state. The exchange officer will usually perform all duties as if he or she were actually in the armed forces to which they are attached. This includes going to war, if required, although this would require that permission be granted from their home government, and that other conditions may be attached. The stated purpose of an exchange officer programme is usually to help foster understanding of each other's operating methods. This provides valuable feedback so that any issues that crop up in joint operations, such as those done under NATO, would not impede the achievement of mission objectives.
The British and the U.S. armed services have many exchange officers; for example, a British officer has been attached to the United States Military Academy at West Point for many years. The Australian Army also attaches one of its officers with the rank of captain to the Royal Military College of Malaysia. Though the Canadian government was stated to be neutral with regards to the Iraq War, many Canadians fought in Iraq under exchange with the U.S. military.
Notable Examples 
Charles Alvin Beckwith, a United States Army officer, Served with the British 22nd Special Air Service regiment during the Malayan Emergency, and eventually took the tactics and real world lessons he learned with the SAS and went on to form the United States Army Delta Force unit.
In 2007 Queen Elizabeth II presented U.S. Marine Major William D. Chesarek Jr. with the Distinguished Flying Cross for his actions in 2006 as an exchange officer flying British helicopters in Iraq.
The United States Navy guided missile destroyer USS Winston S. Churchill has a Royal Navy officer permanently assigned to her crew. The Royal Navy frigate, HMS Marlborough, had a US Navy officer permanently stationed aboard in return until she was decommissioned in July 2005.
The Canadian Forces places an officer as Deputy Commanding General of the US Army's III Corps, a formation similar in size to the entire Canadian military located at Fort Hood, currently BGen. Dean Milner. Fort Bragg's XVIII Airborne Corps also contains a Canadian exchange officer who is designated "Deputy Commanding General Operations", currently BGen. Wayne Eyre. Former Canadian Chief of the Defence Staffs, Generals Rick Hillier and Walter Natynczyk both took part in exchange programs with the US Armed Forces prior to being appointed.
Exchange Officer Programmes 
A programme between the 82nd Airborne Division and the Parachute Regiment of the US Army and British Army respectively. The 82nd Airborne Division also has a similar program with the Australian Army. The UK Royal Marines and US's Marine Corps also have such program, as does the Special Air Service and Delta Force.
In fiction 
- One of Peter Sellers' three characters in Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, Group Captain Lionel Mandrake, is a Royal Air Force exchange officer serving with the United States Air Force.
- The character of Lieutenant Commander Mic Brumby on JAG was an Australian Naval Officer assigned to work with the US Navy Judge Advocate General Corps as part of an officer exchange program.
- In the "A Matter of Honor" episode of Star Trek: The Next Generation, Commander Riker becomes an officer aboard a Klingon Bird-of-Prey as part of an exhange program between the Federation and Klingon Empire. In "Sins of the Father", Worf's brother Kurn becomes first officer aboard the Enterprise.