Internal documents show the Canadian Army was particularly concerned. Over four-year period, commanders in charge of troops in Canada's central and western regions lobbied separately to draw up expanded lists of jobs that would be subject to the enhanced screening.
A spokeswoman for National Defence says the director of military career administration has not made any changes, and the drug-screening program has not been expanded but is subject to continuing review.
Concern about possible drug use among troops over the last few years extended to the top, where the chief of defence staff, now-retired general Walt Natynczyk, "stated that he is receptive to requests to designate other positions or occupations as safety sensitive," said a Nov. 14, 2011, briefing note, obtained by The Canadian Press under the Access to Information Act.
The Forces considered expanding the number of jobs subject to enhanced drug screening in 2007, but was halted because it couldn't justify the invasion of privacy.
The military administer blind drug testing on a regular basis, but the system results in no disciplinary action if the results come back positive. More enhanced screening is given to troops who are in variety of secure positions, and those who deploy overseas.
But according to the briefing note, prepared for the commander of the army, the blind test "does not have the same deterrent effect."
A proposal from land forces central area, which apparently surfaced in May 2011, said a series of blind tests administered to troops not deployed to Afghanistan showed a "a somewhat higher incidence of illicit drug use" and those higher results "were not seen as acceptable" by commanders.
"In their view, one way to respond to these results is to have permanent positions within formations in which (persons) handle weapons, drive, operate complex machinery and combat vehicles, and perform high risk activities be designated as safety sensitive," said the briefing.
The sweeping nature of the proposal required a detailed explanation and justification for each job, the note said. The absence of that sort of rationale doomed to failure an earlier attempt to expand enhanced testing.
"It is the legal requirements surrounding the warrantless intrusion into a member's privacy that demands a higher standard of substantiation and our failure to meet this standard was ultimately responsible for our unsuccessful request in 2007," the note said.
An expert in military law said there are significant privacy implications involved in such a proposal, but they are more than outweighed by the public safety concerns of keeping weapons out of the hands of soldiers suffering with substance abuse problems.
Michel Drapeau, a retired colonel and a leading commentator on access to information, said the military would be within its rights to impose a higher standard test over a wider swath of its ranks.
"People have to know, if they're going to take the paycheque and sign on the dotted line and be trusted these responsibilities, then this one of the things they'll have to do," said Drapeau. "I don't have a problem with that because public interest would come first."
He disagrees with the military on the issue of punishment. As long as enhanced screening is used to spot problems and get soldiers help, it is a useful tool.
"It shouldn't be a tool for disciplinary action," said Drapeau. "If someone hasn't passed the test then it needs to be dealt with compassionately, administratively and medically."
A spokeswoman for defence, Lt.-Cmdr. Meghan Marsaw, said the tests are already given to those in high-risk occupations, such as search-and-rescue technicians and submariners, and that the military does not tolerate illegal drug use.
"Safety is paramount," she said in an email statement. "As such, there are a number of factors taken into consideration when determining whether an occupation is deemed safety sensitive.
"Designating a position or occupation as safety sensitive requires balancing the (Canadian Forces's) interest in safety with the member's privacy and the right to personal security. Generally, positions are designated safety sensitive if the risk to safety is increased by the unauthorized use of drugs."
Statistics have shown the military has far fewer incidents of drug problems when compared with the civilian population.
According to the last report of the Canadian Forces provost marshal, charges of drug use have declined but possession and trafficking charges by military police increased in 2010 when compared with previous years.