In Singapore, the SAF's roots go back to 1854 when the Singapore Volunteer Rifle Corps was formed under colonial rule; the first battalion of regular soldiers, the First Singapore Infantry Regiment, was organized in 1957; the modern SAF was established in 1965 and is today widely viewed as the best equipped military in Southeast Asia; the SAF’s primary responsibility is external defense, but it has trained for certain domestic security operations, including joint deterrence patrols with police in instances of heightened terrorism alerts; the Army is organized into three combined arms divisions and a “people’s defense force,” a divisional headquarters responsible for homeland security and counterterrorism; the Army is based largely on 2-year conscripts and reservists with a small cadre of professional soldiers, and Army units are comprised of a mix of active duty and cadre/reserve battalions that are filled out by reservists upon mobilization; the Air Force and Navy are primarily comprised of professionals; the Air Force has over 100 modern US-origin combat aircraft, plus squadrons for anti-submarine warfare, maritime patrol, early warning, surveillance, and logistical support, as well as unmanned aerial vehicles and attack helicopters; the Navy’s principal combat vessels are a mix of about 20 frigates, corvettes, and littoral combat ships (comparable to a corvette in capabilities), plus about a half dozen submarines; it has additional frigates on order

Singapore is a member of the Five Powers Defense Arrangements (FPDA), a series of mutual assistance agreements reached in 1971 embracing Australia, Malaysia, New Zealand, Singapore, and the UK; the FPDA commits the members to consult with one another in the event or threat of an armed attack on any of the members and to mutually decide what measures should be taken, jointly or separately; there is no specific obligation to intervene militarily (2023)