The Singapore Army is the landservice branch of the Singapore Armed Forces (SAF). It is the largest of the three services and primarily a conscript army that in the event of national exigencies or war, morphs itself from peacetime to a war footing by mobilising almost all of its combined combat power by calling up operationally-ready military reservists.
Two infantry regiments formed the nucleus of the Singapore Army. These were established pre-independence, in anticipation of self-rule following British decolonisation. The First Singapore Infantry Regiment (1 SIR) was formed in 1957, under British auspices. The Second Singapore Infantry Regiment (2 SIR) followed in 1963. After a fraught merger with the Federation of Malaya and subsequent separation in 1965, newly independent Singapore formally established its army by passing the Singapore Army Bill in December 1965. A few months later, the SIR's two active battalions and the Singapore Artillery were joined by a reserve component, the People's Defence Force, formed mostly of volunteers, by then a new incarnation of the old Singapore Volunteer Force that was mobilized for service during the Indonesia–Malaysia confrontation. A third battalion, 10th Battalion PDF, was raised as the volunteer reserve of the Army infantry.
In 1967, the Army began to expand when the National Service programme was officially launched, bringing with it the first conscripted intakes of new recruits to the growing branch. Two years later, the Armoured Regiment was raised becoming the administrative formation of the country's new armoured forces.
In 1972, Parliament passed further legislation (the Singapore Armed Forces Act) to reorganise and consolidate the armed forces' disparate commands and administrative functions.
The Army celebrated its 60th Anniversary in 2017.
1991 Gulf War – Singapore joined other countries as part of the coalition that expelled the Iraqi forces out of Kuwait.
The stated mission of the Singapore Armed Forces is to deter armed aggression, and to secure a swift and decisive victory should deterrence fail. The Army is also tasked with conducting peace-time operations to further Singapore's national interests and foreign policy. These range from disaster relief to peacekeeping, hostage-rescue and other contingencies.
The Army views technology as a force-multiplier and a means to sustain combat power given Singapore's population constraints. Jointness across three branches of the SAF is integral to the Army's warfighting doctrine. Joint operations undertaken with the Navy and Air Force include amphibious landings and critical disaster relief operations in the aftermath of the 2004 Indian Ocean earthquake.
The Army has a technically proficient, relatively well-educated draftee pool and officer corps (non-commissioned and commissioned) reflective of the population at large, and has sought to leverage this to ease its transition into a more sophisticated, networked fighting force.
Combat readiness is a linchpin of Army policy, and military exercises up to divisional level are conducted many times yearly, simulating full-spectrum operations, up to and including full-scale war. Divisional war games are a combined arms, tri-service affair involving the Republic of Singapore Navy and Air Force. Because training space is limited in Singapore—artillery fire would quickly traverse the island—some military exercises are conducted overseas. Reservists periodically  train abroad, their units regularly evaluated for combat readiness. The Army also trains bilaterally with some host nations, and military exchanges are frequent. Training is billed as "tough, realistic and safe," with a premium on safety, given the sensitivity of military deaths in a largely conscript army.
Following the Revolution in Military Affairs, and in tandem with modernizing its weapons systems, the Army is forging a transition to a more network-centric fighting doctrine that better integrates the Air Force and Navy.
The Army is headed by the Chief of Army (COA). In the past, the Army was head by the Deputy Chief of the General Staff (Army). Assisting him are the Chief of Staff, General Staff and Commander, TRADOC (Army Training and Doctrine Command). There are six branches of the General Staff (G1-G6), a National Service Affairs Department (G8) dealing with National Service issues, and an Inspectorate. The six branches handle manpower (G1), intelligence (G2), operations (G3), logistics (G4), planning (G5) and training (G6) respectively. Each department is headed by an Assistant Chief of the General Staff (ACGS). Also advising the Chief of Army are the Senior Specialist Staff Officers (SSSOs) of the various formations (Infantry, Guards, Armour, Commandos, Artillery, Combat Engineers, Maintenance & Engineering, Transport, Supply and Signals).
The Army's main organizational components are its Combined-Arms Divisions, of which there are three active:
the 3rd, 6th and 9thDivisions. They include both active and reserve units that are operationally ready, all subject to mobilization orders in the event of war.
2 People's Defence Force (PDF) is responsible for homeland security, including that of key civilian installations and infrastructure. 2 PDF is also responsible for the coordination and secondment of military resources to civilian agencies in the event of a civil emergency.
Army Deployment Force - A high readiness, regular only unit that provides the Army with specialised capabilities for a full spectrum of Operations. Including but not limited to, Support for Special Operations Task Force (SOTF), Peace-Time Contingency Operations (PTCO), Peace Support Operations (PSO) and Humanitarian Assistance and Disaster Relief (HADR) missions.
Aggressor Company – subordinate to TRADOC/ATEC, this company-sized detachment organizes itself according to the hypothesized enemy's order of battle and acts as the OPFOR in training evaluations. They are the 'red' opposing force in ATEC evaluations.
^S. M. Maran; Koh Boon Pin (2000). S. M. Maran; Santokh Singh; Goh Choon Lee; Koh Boon Pin; Chao Ning; Ng We Yuan (eds.). LIONS IN DEFENCE: THE 2 PDF STORY. 2 PDF Command Officers' Mess. Retrieved 25 September 2018.