Question: What military force did Rosemary Pratt's husband serve in?

Context paragraphs:
Royal Johor Military Force: The Royal Johor Military Force (Malay: "Askar Timbalan Setia Negeri Johor"; Jawi: "عسكر تيمبالن ستيا نڬري جوهر") is an independent military force raised in 1886 by Abu Bakar of Johor.  The RJMF is believed to be the oldest military unit in Malaysia and is the only "state army" in the Federation The Force comes under the control of the Sultan of Johor.  Its headquarters are located at Bukit Timbalan, Johor Bahru, Johor.  The retention of the army was one of the stipulations in 1946 which Johor made when it participated in the Malay Federation.  No other Malaysian state has their own army.

Missouri Reserve Force: The Missouri Reserve Force, originally known as the Military Reserve Military Force, is the official state defense force of Missouri.  As a state defense force, the MRF is a reserve military force which serves parallel to the Missouri National Guard.  MRF members serve as reservists and therefore can hold full-time jobs while serving, like their National Guard counterparts.  As the MRF falls solely under the command of the state of Missouri, it cannot be federalized or deployed outside the borders of Missouri, unlike the National Guard.  Although the MRF and the Missouri National Guard are separate organizations, the MRF's primary scope is to work alongside the National Guard during stateside operations, or in lieu of the National Guard when the National Guard is deployed outside of Missouri.  Along with the Missouri Army National Guard, the Missouri Air National Guard, and the Missouri Naval Militia, the Missouri Reserve Force is recognized under Missouri law as part of the organized militia of Missouri.

Humanitarian intervention: Humanitarian Intervention has been defined as a state's use of "military force (publicly stated that its use is for ending the violation of human rights) against another state."  This definition may be too narrow as it precludes non-military forms of intervention such as humanitarian aid and international sanctions.  On this broader understanding, "Humanitarian intervention should be understood to encompass… non-forcible methods, namely intervention undertaken without military force to alleviate mass human suffering within sovereign borders."

Peace enforcement: Peace enforcement is the use of military force to compel peace in a conflict, generally against the will of those combatants.  To do this, it generally requires more military force than peacekeeping operations.  The United Nations, through its Security Council per Chapter VII of its charter, has the ability to authorize force to enforce its resolutions and ceasefires already created.

Rosemary Pratt, Marchioness Camden: Rosemary Pratt, Marchioness Camden (9 May 1921 – 27 February 2004), born Cecil Rosemary Pawle, was a British socialite and artist, best known as the first wife of Group Captain Peter Townsend, who later became romantically involved with Princess Margaret of the United Kingdom.

Peter Townsend (RAF officer): Group Captain Peter Wooldridge Townsend, (22 November 1914 – 19 June 1995) was a Royal Air Force officer, flying ace, courtier and author.  He was Equerry to King George VI from 1944 to 1952 and held the same position for Queen Elizabeth II from 1952 to 1953.  Townsend also had a romance with Princess Margaret.

Maine State Guard: The Maine State Guard was the state defense force of the state of Maine during World War I, World War II, and the Vietnam War.  As a state defense force, the State Guard served as a stateside replacement for the Maine National Guard when the National Guard was federalized.  Like the National Guard, the State Guard was a reserve military force composed of members who held full-time civilian jobs and periodically met for drills, unless called into active service by the governor.  However, unlike the National Guard, as a state defense force, the Maine State Guard was solely a state military force, which was immune from federalization and could not be deployed outside the state of Maine.

Embarked military force: An embarked military force is a military force that is carried by an amphibious assault ship.  It may include troops, vehicles and other equipment.

Sultan of Johor: The Sultan of Johor is a hereditary seat and the sovereign ruler of the Malaysian state of Johor.  In the past, the sultan held absolute power over the state and was advised by a "bendahara".  Currently, the role of "bendahara" has been taken over by chief minister (Malay: "Menteri Besar") with the constitutional monarchy system via Johor State Constitution.  The Sultan is the constitutional head of state of Johor.  The Sultan has own independent military force Royal Johor Military Force (Malay: "Askar Timbalan Setia Negeri Johor").  The Sultan is also the Head of Islam in Johor state.

South Dakota State Guard: The South Dakota State Guard is the currently inactive state defense force of South Dakota.  The State Guard is recognized as a military force separate from the South Dakota National Guard.  Unlike the National Guard, the State Guard is a purely state-level military force under the command of the Governor of South Dakota, and cannot be federalized or deployed outside the borders of the state.  The South Dakota State Guard was active during World War I, World War II, and the Vietnam War and provided military protection to the state of South Dakota while the National Guard was in federal service.

Supporting paragraphs: Rosemary Pratt, Marchioness Camden Peter Townsend (RAF officer)
Answer: Royal Air Force