Total Defence is a cornerstone of Singapore’s national security policy and practice. As a ‘Whole-of-nation’ framework, it has evolved to deal with the increasing complexity of national security risks and challenges.
In 1984, Total Defence (TD) was introduced in Singapore as a “national defence concept” to strengthen the nation in the face of external military aggression. To date, Singapore is one of the few non-Western countries to have adopted TD as a comprehensive defence strategy. Moreover, TD has consistently been sustained and revitalised for more than forty years. Adapted from the comprehensive defence strategies of Switzerland and Sweden, the primary focus of TD in its early years (1980s to 1990s) was to mobilise the nation and its resources behind the Singapore Armed Forces (SAF) in the event of a conventional attack against the country – including through the so-called National Service (NS), a two-year full time military or civil defence service.
From the 2000s onward, however, there was growing recognition that societal factors – particularly the people’s determination to protect the nation’s way of life – were just as important to TD. This interrelationship between NS, TD, and protecting Singapore’s way of life was emphasized by then Prime Minister Lee Hsien Loong in his 2012 NS45 Commemoration Speech, where he highlighted the need for every Singaporean to “be committed to the defence of Singapore, whether it is military defence, civil defence, economic, social or psychological defence”.
In addition to military, civil, economic, social, and psychological defence, a sixth pillar – digital defence – was added to Singapore’s TD concept in 2019.
At its inception, TD consisted of five pillars: (1) Military Defence relies on a strong and credible SAF to deter aggression and protect the country. (2) Civil Defence aims to prepare the population for emergencies and being effective first responders when a crisis occurs. (3) Economic Defence is about strengthening the competitiveness and attractiveness of Singapore’s economy, which is critical for Singapore’s survival and success. (4) Social Defence aims to build understanding and trust amongst citizens across all ethnic groups. (5) Psychological Defence is based on a strong shared identity as Singaporeans and the will to defend the Singapore way of life and aims to build a cohesive society that can overcome crises together. In addition to military, civil, economic, social, and psychological defence, a sixth pillar – digital defence – was added to Singapore’s TD concept in 2019. As Singapore entered the 21st century, TD evolved from a national-defence-centric framework to a whole-of-nation approach aimed not only at safeguarding its sovereignty, but also at strengthening the country’s ability to absorb shocks and recover from crises and emergencies. There was a growing recognition that the impact of national security challenges would increasingly manifest in the socio-economic domain, requiring a more holistic response and the adaptation of existing structures such as TD. Over the past four decades, TD has thus continued to evolve as a whole-of-nation framework capable of addressing conventional, non-conventional and emerging threats.
From National Defence to Whole-of-Nation Resilience
The diffuse nature of transnational terrorism, cyberattacks and hybrid threats – including malign foreign influence and cognitive warfare – together with the profound impact of the COVID-19 pandemic drove successive adaptation to TD. Over time, the concept gradually evolved from a defence-centred framework into a whole-of-society approach. In recent years, particular emphasis has been placed on psychological defence, social cohesion and maintaining trust in societal and governmental institutions, reflecting concerns about polarisation that continue to challenge democratic societies.
Since Singapore’s independence, strengthening its social cohesion has been an ongoing collective effort involving the whole-of-society.
Singapore’s multicultural make-up, open economy and global connectivity to the world place it in a particularly vulnerable position to hybrid attacks. In 2015, Singapore’s Defence Minister Dr Ng Eng Hen drew attention to the term hybrid warfare, which he described as “an orchestrated campaign to fracture the solidarity of the target nation through undermining its defences in civil, economic, social, psychological and military spheres”. These threats seek to exploit perceived vulnerabilities and fault lines in politics and society as well as the individual’s cognitive domain which is inherently difficult to protect. Singapore is therefore no stranger to hostile information campaigns and coordinated foreign interference in its domestic politics. In addition, according to the Singapore Terrorism Threat Assessment Report 2025, the terror threat remains high.
Against this backdrop – marked by hybrid threats, online falsehoods, and the threat of terrorism – psychological defence has assumed heightened importance. Then Second Minister for Defence Ong Ye Kung defined it as the “ability of people to trust each other, have faith in societal and government institutions, and remain resilient against forces seeking to sow discord and division”. This dimension has become increasingly central in an era where conflict is being waged through non-military means. Since Singapore’s independence, strengthening its social cohesion has been an ongoing collective effort involving the whole-of-society.
Cultivating Cross-Sectoral Capabilities
In 2022, the Digital and Intelligence Service (DIS) was established as fourth service branch of the SAF (in addition to the Army, Navy, and Air Force) to raise, train, and sustain digital forces and capabilities. Critical Infrastructure Defence Exercises (CIDex) organised by DIS and the Cyber Security Agency of Singapore (CSA) help cultivate cross-sectoral practitioners in cybersecurity by bringing together stakeholders from across government and industry to exercise scenarios involving attacks on critical infrastructure, including power supply, railway services and 5G networks.
In 2025, DIS inaugurated the Defence Cyber Command (DCCOM) consolidating military cybersecurity entities under a single command to more effectively advance cyber capabilities and operations. These entities included the Cyber Protection Group, which contributes to national cyber defence by working with the CSA and other government agencies to strengthen the resilience of key Critical Information Infrastructure, and the Cyber Threat Intelligence Group, which provides early warning and assessments of emerging cyber threats.
The inaugural exercise SG Ready, held from 15 to 29 February 2024, simulated disruptions to power, water, food supply and digital connectivity, with the aim of encouraging individuals, communities and businesses to plan and operationalize their own contingency plans. Initiatives such as SG Ready illustrate how TD is continually practiced in Singapore to strengthen preparedness for disruptions to essential services and critical infrastructure. In the 2025 iteration of SG Ready, conducted from 15 to 28 February 2025, over 800 organisations, schools and units across businesses and government carried out disruption and preparedness activities. These exercises focused on strengthening business continuity planning, particularly in response to scenarios such as power disruptions or phishing attacks.
In the Ministries’ Addenda to the President’s Address of the 15th Parliament on 5 September 2025, the Ministry of Defence (MINDEF), Ministry of Home Affairs, Ministry of Foreign Affairs (MFA) and the National Security Coordinating Secretariat (NSCS), outlined key initiatives and priority areas under the theme of “Securing Singapore’s Place in a Changing World”. Several of the initiatives already build on fundamentals such as NS and TD. Beyond strengthening NS and enhancing military readiness, the MINDEF remains focused on building whole-of-nation resilience, preparing Singapore for crises and disruptions, and upholding collective resilience via TD.
As an adaptive whole-of-nation framework, TD has consistently been invoked in response to a wide range of national security challenges, including pandemics, transnational terrorism, cyberattacks, and hybrid threats.
Similarly, in the foreign policy domain, the MFA remains central in engaging Singaporeans to foster better understanding of Singapore’s core foreign policy considerations and maintain national unity to withstand external pressures. Looking ahead, emerging and cross-cutting security challenges that span across multiple domains will continue to test the capabilities of coordinating bodies such as the NSCS to respond in a coherent and effective manner.
Conclusion
As an adaptive whole-of-nation framework, TD has consistently been invoked in response to a wide range of national security challenges, including pandemics, transnational terrorism, cyberattacks, and hybrid threats. The recent addition of digital defence reflects the evolution of TD in response to the growing sophistication of AI-enhanced disinformation and influence operations, reinforcing its relevance as a whole-of-nation framework in both concept and practice. At its core, however, TD’s focus remains on building resilience, maintaining public trust and enhancing coordination as well as collaboration amongst government agencies, individuals, businesses and communities.
