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Stability does not come naturally to Singapore. We are peculiarly vulnerable. If our balance of security and stability is shattered It is doubtful if we on our own can ever put Singapore together again. Former Prime Minister Lee Kuan Yew (1987)

Our Mission

Our mission is to keep Singapore safe and sovereign for all Singaporeans. To do so, we collect accurate intelligence, make impartial assessments and take timely action to counter security threats. We do this, without fear or favour, because we passionately believe that Singapore belongs to all its citizens regardless of colour or creed, and that for a small, multi-racial city state, our collective survival hinges on continued stability and security.  

As ISD officers we cherish the character qualities of Integrity, Courage, Loyalty, and Self-Sacrifice, for ours must always be a cause greater than our self.

Our Role


ISD confronts and addresses threats to Singapore’s internal security and stability. For over 70 years, ISD and its predecessor organisations have played a central role in countering threats such as those posed by foreign subversive elements, spies, racial and religious extremists, and terrorists. 

At the heart of our work are the collection of intelligence that enables us to size up the threats to Singapore’s internal security, and taking the executive actions necessary to overcome those threats. Every day, we collect and analyse intelligence, make impartial assessments, and take decisive action to counter the threats to Singapore’s internal security and stability, and sovereignty.  


Our History

“ISD’s vigilance and interventions have kept Singapore safe and secure, and allowed our nation to develop and grow.”

Prime Minister Lee Hsien Loong (2008)

ISD’s history is inextricably intertwined with Singapore’s security history. We trace our roots to the Criminal Intelligence Department (CID) of the colonial police service, which was set up in 1918 in the wake of what was named the Sepoy Mutiny of 1915. The CID was renamed Special Branch in 1933 to reflect its responsibility in dealing with a range of pre-war threats posed by communists, seditionists and spies.


Early pioneer officers such as (from left to right) Director of CID Rene Onraet, Chief Inspector Prithvi Chand, Chief Inspector Balwant Singh and Senior Asiatic Inspector Wong Chin Yoke were involved in the fight against seditionists, spies and subversives during the pre-war period. 

During Singapore’s tumultuous road to independence after World War II, the Singapore Special Branch dealt with internal security threats arising from communal (racial and/or religious) tensions, communist subversion and foreign operatives looking to wreak havoc here during the period known as Konfrontasi.



Vehicles were set on fire and damaged during the Maria Hertogh Riots.

On 17 February 1966, after Separation from Malaysia, the Singapore Special Branch was renamed the Internal Security Department (ISD). ISD had to grapple with serious security challenges confronting a fledgling nation. With the Cold War in full swing, the Communist Party of Malaya continued to pose a serious threat to national security with its campaign of violence. Foreign countries, even friendly ones, attempted to influence our domestic politics. Terrorism also reared its ugly head as Singapore became a target for hostile actors and extremist militant groups.

ISD has safeguarded Singapore’s internal security, stability and sovereignty for decades. We continue to do so, as the longstanding security threats of terrorism, communal extremism, foreign subversion and interference, and espionage, persist and evolve while new threats emerge in an increasingly complex world.