It is responsible for gathering, processing, and analyzing national security information from around the world and conducting covert action within Canada and abroad.

[8] In its early years, its primary focus was on investigating terrorist groups in response to a number of violent crimes with political undertones, such as the bombing of an Air India jet departing from Montréal and the armed takeover of the Turkish embassy in Ottawa.

The institutional focus of CSIS returned to state actors (such as Russia and China) after a February 2021 speech by the CSIS director, David Vigneault, who warned that the Chinese "strategy for geopolitical advantage on all fronts — economic, technological, political and military" uses "all elements of state power to carry out activities that are a direct threat to our national security and sovereignty.

[24][25] CSIS is one of several federal agencies (primarily those involved with law enforcement, security, or having a regulatory function) that have been granted a heraldic badge.

[27] In the book, The Mosaic Effect, co-authors, former Canadian Military Security Intelligence Analyst, Scott McGregor and Journalist Ina Mitchell revealed that employees' internal nickname for CSIS is "the Sisters.

Examples of some of the countries they have served in are: Afghanistan, Iraq, Syria, Lebanon, Mali, Libya, Sudan, Pakistan, Somalia, Qatar, Kuwait and the United Arab Emirates.

The agency carries out its functions in accordance with the Canadian Security Intelligence Service Act, which governs and defines its powers and activities.

Global Affairs Canada maintains a Security and Intelligence Bureau to review and analyze overtly acquired information.

The flight carried 329 people, including 268 Canadians, many of whom were children, young adults, and families traveling to visit relatives and friends during the summer vacation season.

The Air India bombing remains one of the deadliest terrorist attack in Canadian history, but it also exposed significant lapses in intelligence and security measures.

The Canadian Security Intelligence Service (CSIS), established only a year earlier in 1984, faced criticism for its failure to prevent the attack.

[40] The tapes could have provided crucial evidence during investigations and trials but were erased as part of routine policy, a move widely criticized as negligent.

The lack of coordination between CSIS and the Royal Canadian Mounted Police (RCMP) also hindered efforts to thwart the bombing.

Intelligence gathered by CSIS was not effectively shared or acted upon, highlighting systemic issues in Canada’s counterterrorism framework.

[43] These regions are responsible for investigating any threat to Canada and its allies as defined by the Canadian Security Intelligence Service Act.

They also conduct various outreach programs with different community and cultural groups, universities, and private sector organizations in an effort to provide a better understanding, and to clear up any misunderstandings of the role of CSIS.

[47] CSIS officers stationed in foreign flashpoints, such as Afghanistan, carry unspecified guns, however they are not authorized to bear arms inside Canada.

[citation needed] The RAP was reorganized in 1996–1997 in order to better coordinate with the Intelligence Assessment Secretariat of the Privy Council Office.

[51] As part of an omnibus national security bill passed by the Parliament in 2019, the oversight and reporting regime for CSIS was overhauled.

The reforms also included the creation of a new Intelligence Commissioner who reports to Parliament and has quasi-judicial oversight of all national security matters.

The committee performs strategic and systematic reviews of the legislative, regulatory, policy, expenditure and administrative frameworks under which national security activities are conducted.

According to L'Hebdo Journal, it is reported that some senior officials of the service used a bunker in Ottawa to file and discuss warrant applications with judges of the Federal Court.

[59] Crown prosecutor James Jardine expressed frustration with CSIS to the Commission of Inquiry into the Investigation of the Bombing of Air India Flight 182, headed by Justice John C. Major.

The agent, Grant Bristow, built relationships with far-right activists and white supremacists involved in the Nationalist Party of Canada, before breaking off with them to form the Heritage Front.

[60][61][62] In 1997, the Royal Canadian Mounted Police collaborated with CSIS on Project Sidewinder, a study alleging China had set up a foreign influence network in Canada.

[citation needed] The commission found that US authorities sent Arar to Jordan and then Syria (his country of birth) based on incorrect information which had been provided by the RCMP to the US government.

[71] Prominent Canadian national security lawyer Barbara Jackman has also been critical, categorizing the research by CSIS as "sloppy" and that its officers are "susceptible to tunnel vision".

[74] In June 2023, a prominent Sikh leader, Hardeep Singh Nijjar, was murdered outside a temple in British Columbia, Canada by unidentified gunmen.