It said this on Friday in response to queries from the media, after Malaysia announced the abolition of the ISA on Thursday.
The Home Affairs Ministry said that Singapore and Malaysia are different, even though the ISA has the same roots for when both countries were British colonies.
It said the respective societies have evolved. Even the Act itself has evolved.
For example, a person arrested under the ISA in Singapore may be held in custody for up to 30 days, after which a Detention or Restriction Order must be issued or else the person must be released unconditionally.
In Malaysia, the period of custody is double – up to 60 days.
In addition, in Singapore, the President can veto the government’s decision.
The ministry added that Singapore has used the ISA sparingly. It said no one has ever been detained only for their political beliefs.
The ISA has been used to deal with threats of subversion, racial and religious extremism, espionage and terrorism, and these threats continue to be salient today, the ministry said.
It added that the ISA was used effectively in 2001 to thwart the imminent suicide bombings planned by Al-Qaeda and Jemaah Islamiyah.
Like Malaysia, there have been calls among certain quarters in Singapore to abolish the ISA. They include civil liberty groups and political parties, who argue the law has lost its relevance.
However, one terrorism expert MediaCorp spoke to said it is “foolish” of Malaysia to abolish the ISA.
Dr Rohan Gunaratna, from the International Centre for Political Violence and Research, said: “Today, there are only two countries in Southeast Asia that have been severely threatened by terrorism, but have prevented terrorist attacks. One is Malaysia and the other is Singapore.
“So ISA is an invaluable tool to preventively detain terrorist suspects to investigate and also to confine them. If this important piece of law is taken out of the equation, it will not benefit governments to fight terrorism effectively.
Dr Rohan added that there is a heightened threat of terror in the region now, so it is important to keep the ISA until such threats diminish.
Meanwhile, Singapore’s opposition Workers’ Party, which had called for the abolition of the ISA in its election manifesto, said that even with such a move, there should be effective measures against terrorism.
In a posting on its Facebook page, it repeated its call for a dedicated anti-terrorism law to make swift arrests and detain suspects without trial.
But these suspects must be afforded real avenues to challenge the legality of their arrests through the courts and an advisory board, said the party.