Military science
Recruitment and retention: In an all-volunteer military, the armed forces relies on market forces and careful recruiting to fill its ranks. It is thus, very important to understand factors that motivate enlistment and reenlistment. Service members must have the mental and physical ability to meet the challenges of military service and adapt to the military's values and culture. Studies show that enlistment motivation generally incorporates both self-interest (pay) and non-market values like adventure, patriotism, and comradeship.

Veterans: The study of veterans or members of the military who leave and return to the society is one of the most important subfields of the military and society field of study. Veterans and their issues represent a microcosm of the field. Military recruits represent inputs that flow from the community into the armed forces, veterans are outputs that leave the military and reenter society changed by their time as soldiers, sailors, marines and airmen. Both society and veteran face multiple layers of adaptation and adjustment upon their reentry.
The definition of veteran is surprisingly fluid across countries. In the US, veteran's status is established after a service member has completed a minimum period of service. Australia requires deployment to a combat zone. In the UK "Everyone who has performed military service for at least one day and drawn a day's pay is termed a veteran." The study of veterans focuses much attention on their, sometimes, uneasy transition back to civilian society. "Veterans must navigate a complex cultural transition when moving between environments," and they can expect positive and negative transition outcomes. Finding a good job and reestablishing a fulfilling family life is high on their resettlement agenda.
Military life is often violent and dangerous. The trauma of combat often results in post-traumatic stress disorder as well as painful physical health challenges which often lead to homelessness, suicide, substance, and excessive alcohol use, and family dysfunction. Society recognizes its responsibilities to veterans by offering programs and policies designed to redress these problems. Veterans also exert an influence on society often through the political process. For example, how do veterans vote and establish party affiliation? During the 2004 presidential election veterans were basically bipartisan. Veterans who fought in Croatia's war of independence voted for the nationalist parties in greater numbers.

Reserve forces: Reserve forces are service members who serve the armed forces on a part-time basis. These men and women constitute a "reserve" force that countries rely on for their defense, disaster support, and some day-to-day operations etc. In the United States an active reservist spends a weekend a month and two weeks a year in training. The size of a county's reserve force often depends on the type of recruitment method. Nations with a volunteer force tend to have a lower reserve percentage.
Recently the role of the reserves has changed. In many countries it has gone from a strategic force, largely static, to an operational force, largely dynamic. After WWII, relatively large standing forces took care of most operational needs. Reserves were held back strategically and deployed in times of emergency for example during the Cuban missile crisis. Subsequently, the strategic and budget situation changed and as a result the active duty military began to rely on reserve force, particularly for combat support and combat service support. Further large-scale military operation, routinely mobilize and deploy reservists 
Lomsky-Feder et al (2008p. 594) introduced the metaphor of reserve forces as transmigrants who live "betwixt and between the civilian and military worlds". This metaphor captures "their structural duality" and suggests dynamic nature of reservist experience as they navigate commitments to their often conflicting civilian and military worlds. Given their greater likelihood of lengthy deployment, reservists face many of the same stresses as active duty but often with fewer support services.

University studies: Universities (or colleges) around the world also offer a degree(s) in military science:

Belgium: Royal Military Academy (Belgium)- BA Social and Military Science; MA Social and Military Science
Israel:
Tel Aviv University – MA in Security.
Bar-Ilan University – MA in Military, Security and Intelligence.
Finland:
National Defence University – Bachelor, Master, and PhD in Military science
France:
Sciences Po, Paris School of International Affairs - Master in International Security.
New Zealand:
Massey University, Centre for Defence and Security Studies – BA in Defence Studies.
Victoria University of Wellington – Centre for Strategic Studies – Master of Strategic Studies (MSS).
Slovenia:
University of Ljubljana, Faculty of Social Studies – BA, MA and PhD in Defence studies; PhD in Military-Social Sciences
United Kingdom:
King's College London – MA in International Security and Strategy; MA, MPhil/PhD in Defence Studies
University of Hull – MA in Strategy and International Security
University of St Andrews - MLitt in Strategic Studies
Sri Lanka
Sri Lanka Military Academy - (Bachelor and Master's degree in Military Studies) Military training school Diyatalawa, Sri Lanka
South Africa
South African Military Academy / University of Stellenbosch - Bachelor of Military Science (BMil), Master of Military Science (MMil), MPhil in Security Management 
United States:
United States Air Force Academy – Major in Military and Strategic Studies; Minor in Nuclear Weapons and Strategy
United States Military Academy – Major in Defense and Strategic Studies
Hawaii Pacific University – Major in Diplomacy and Military Studies
Missouri State University – Minor in Military Studies

International military sciences or studies associations: There are many international associations with the core purpose of bringing scholars in the field of Military Science together. Some are inter-disciplinary and have a broad scope, whilst others are confined and specialized focusing on more specific disciplines or subjects. Some are integrated in larger scientific communities like the International Sociological Association (ISA) and the American Psychological Association (APA) where others have grown out of military institutions or individuals who have had a particular interest in areas of military science and are military, defense or armed forces oriented. Some of these associations are:

American Psychological Association; Division 19: Society for Military Psychology (APA-Div19)
European Research Group on Military and Society (ERGOMAS)
Inter-University Seminar on Armed Forces and Society (IUS)
International Congress on Soldiers Physical Performance (ICSPP) 
International Military Testing Association (IMTA)
International Society of Military Sciences (ISMS)
International Sociological Association; RC01 Armed Forces and Conflict Resolution

Military studies journals: The following are notable journals in the field:

See also: Military doctrine
Military theory
War
List of basic military science and technology topics
List of military inventions
List of military writers
Philosophy of war

References: Notes

Bibliography

External links: 
Military Technology
US Military/Government Texts

The Logic of Warfighting Experiments by Kass (CCRP, 2006)
Complexity, Networking, and Effects Based Approaches to Operations by Smith (CCRP, 2006)
Understanding Command and Control by Alberts and Hayes (CCRP, 2006)
The Agile Organization by Atkinson and Moffat (CCRP, 2005)
Power to the Edge by Alberts and Hayes (CCRP, 2003)
Network Centric Warfare by Alberts et al. (CCRP, 1999)