The world view of the al Qaeda Islamic terrorist network was set forth in its "Letter to America" of November 2002. It proclaimed that the ultimate objective of its terror is to force the Islamization of the United States, followed by pursuit of the same objective for other non-Islamic countries. Canada's open and tolerant multicultural society, which includes large ethno-religious communities from throughout the world, makes the country vulnerable to infiltration by international terrorist networks. Virtually all of the most notorious international terrorist organizations are known to maintain a network presence in Canada. The primary responsibility for counterterrorism is vested in the Canadian Security Intelligence Service (CSIS), in intelligence collection, and the Royal Canadian Mounted Police (RCMP), in law enforcement. These agencies work with other elements of the security and intelligence community, pertinent government departments, international coalition partners and allies, and local police forces. Following the September 11 terrorist attack on the United States, the Canadian Government committed substantially increased resources to the security and intelligence and law enforcement communities to bolster their counterterrorism functions. A significant share of these resources is for revitalizing and expanding the capabilities of the security, intelligence, and law enforcement agencies. Canada has also adopted new antiterrorism legislation designed to equip intelligence agencies and police forces with enhanced statutory powers for surveillance, investigation, and arrest. Increased attention has also been given to illicit fundraising and money laundering that supports international terrorism. The political sustainability of Canada's counterterrorism effort over the long term may depend on the building of public awareness of the terrorist threat and support for the measures needed to counter the tactics of terrorist networks, whose planning and organizing must be disrupted through proactive intelligence and law enforcement, since failure to prevent a terrorist attack can be catastrophic.