If terrorism suspect Momin Khawaja, now on trial in Ottawa, is as guilty as Crown prosecutors say, it'll be time to settle an important question: Was Mr. Khawaja a "Naji man"?

Amid trial allegations, court details and defence objections, significant questions arise about Mr. Khawaja's status as a consultant to the Department of Foreign Affairs at about the time of his arrest. Prosecutors claim the software contractor used his perch inside the department to send streams of E-mails to confederates abroad - that federal resources were, in other words, used to advance terror plots. Authorities also say Mr. Khawaja might have used privileged Foreign Affairs department travel documents to travel on his "missions." And that he allegedly suggested using special departmental courier services to send bomb-related equipment to foreign associates, in the apparent belief that a government imprimatur on shipments confers immunity from customs searches.

Insiders can do a lot of damage in sensitive government and private-sector establishments. From intelligence organizations to banks, history is replete with examples of infiltrators and penetrators undermining computer systems, removing money, spilling secrets. Remember Barings Bank? Kim Philby?

So questions must be asked. If, for the sake of argument, Mr. Khawaja was working against Canadians and their allies, what access did he have to departmental personnel, to electronic records, communications and associated encryption systems? Who recommended and hired him in the first place? A friend? If the government's version is correct, why would a software consultant be so confident about his access to special courier services? Did he have a network of friends at the department? It is early days, and no decisive answers are on offer.

But these things must be asked whenever a possible radical or extremist Islamist breach of security is hinted at, and here's why: Islamic extremists and subversives place great emphasis on infiltrating social, political, economic and security apparatuses of target nations, like Canada, with a view to manipulating and undoing their infrastructure.

Last year's dramatic Holy Land Foundation trial in Texas made the point. There, U.S. prosecutors put klieg lights on previously secret strategic documents seized from extremist Muslim Brotherhood (MB) sources. This subversive worldwide organization is the font from which spring a number of hardline "mainstream" North American Islamic front groups and "representative organizations," including many recently defined as unindicted co-conspirators by the U.S. Justice Department - and some, amazingly, periodically engaged in "outreach" by unsuspecting interfaith and even government officials.

The prize U.S. document was the Brotherhood's 1991 long-term plan to subvert and collapse the United States and its political, economic and other infrastructure, preparatory to achieving a forced radical Islamicization of that country, and others. Through a malign combination of immigration, intimidation, psychological warfare and subterfuge, the MB proposed "settling" - colonizing - the U.S., infesting its infrastructure, and relying on societal openness, constitutional freedoms and influence operations to proceed from there: "The process of settlement is a 'Civilization-Jihadist Process'," said the memorandum, adding ominously, "with all the word means."

The Brothers, it continued, "must understand that their work in American [sic] is kind of a grand Jihad in eliminating and destroying the Western civilization from within and sabotaging its miserable house by their hands and the hands of the believers so that it is eliminated and God's religion is made victorious over all other religions."

More recently, Abu Bakr Naji, al-Qaeda's senior operational strategic thinker, explained the priority. Radical Islamists are to be "infiltrating the adversaries and their fellow travelers and establishing a strong security apparatus" to support the underground movement, now, and the resulting theocratic Islamic state, later. "[We] should infiltrate the police forces, the armies, the different political parties, the newspapers, the Islamic groups, the petroleum companies ... private security companies, sensitive civil institutions, etc."

"That," concludes Mr. Naji chillingly, "actually began several decades ago, but we need to increase it in light of recent developments."

Indeed, Muslim Brotherhood-inspired organizations were being set up on this continent as far back as the 1960s, and considerably earlier elsewhere. By now, there is little doubt that many "Naji men" -- and women -- are ensconced in the West, and recent developments cause concern:

- a police officer in the northeastern U.S., helping a terror suspect at his mosque to identify federal surveillance vehicles;

- an American 911 operator conducting illegal watch-list and other database searches, and communicating the results, illicitly;

- and questions about jihadist sympathies among certain figures in the FBI and CIA, the State Department and U.S. Muslim military chaplain corps, the White House, Homeland Security, the U.S. Air Force, Guantanamo, and the Federal Bureau of Prisons. (For details see this Investor's Business Daily editorial on the subject: http://www.ibdeditorials.com/IBDArticles.aspx?id=280367130714172.)

Canadians must guard against infiltration of government, business and associated infrastructure. Mr. Naji's operational aims bring home the need to make realistic determinations about the reliability of those employed in military and security offices, in nuclear-energy and power-grid control rooms, and in virus and biochemical research labs - even about those influencing politicians and decision-makers.

We cannot guess the outcome of the Khawaja trial, but perhaps evidence of Mr. Khawaja's work in government will encourage an overdue debate about Canada's counterpenetration strategy. We should begin now, while relative peace allows us to do so in an ordered, balanced and effective way.

David Harris is president of Democracy House, and a lawyer involved in national security matters. He is counsel to the Canadian Coalition for Democracies and a former senior CSIS official.