Two former Liberal defence ministers say the time is right for Canada to join the U.S. government's ballistic missile shield program.
Bill Graham and David Pratt testified before a Senate security and defence committee on Monday, saying Canada should revisit the matter.
Their voices are joining the debate as the governing federal Conservatives appear to be trying to gauge the Canadian public's appetite for joining the U.S. missile defence program.
It was the former Liberal government of Paul Martin that publicly rejected joining the program in 2005.
And on Monday it was Mr. Martin's defence minister who urged Canada to change course.
"The ultimately security of Canada within the North American context is better off when we're participating with the Americans in the development of these systems that are designed to protect North America as a whole," Mr. Graham told reporters after his appearance at the Senate committee.
Both Mr. Graham and Mr. Pratt, who held the post during Jean Chrétien's administration, say they were hamstrung in their day by antipathy among Canadians toward then-U.S. president George W. Bush.
Mr. Bush, a right-wing Republican, lost ground in popularity after leading a coalition of countries into a war in Iraq.
"It was very much in the context of the Bush years and the Bush administration, and we kind of forget that. Just to put it bluntly, if it had been President [Barack] Obama asking for it with this approach, you never know – we might have said yes," Mr. Graham said.
Conservative-dominated committees in both the Senate and Commons are examining the merits of the U.S. missile defence program. Both committees are studying broader security matters but have been hearing witnesses on missile defence as part of their research.
Advocates in Canada say the federal government should join the U.S. program to ensure that the missile defence system, which aims to protect the United States, among other regions, from North Korean or Iranian missiles, is also programmed to keep incoming strikes away from Canadian soil.
James Bezan, the Parliamentary Secretary to the Minister of Defence, said Ottawa is concerned that under the current arrangement Canadian officials would be "sidelined" in the decision-making on the response to any missile threat incoming to North America.
Mr. Pratt said he hopes that Prime Minister Stephen Harper considers signing up on behalf of Canada, adding that he hopes his and Mr. Graham's testimony makes it easier to embrace missile defence.
"We're approaching another election, obviously, so the timing is not terribly auspicious that way, but Mr. Harper does have a majority government and he's hearing from two former Liberal defence ministers that missile defence is probably a good thing to do from the standpoint of our national security, and the Canada-U.S. binational defence relationship," Mr. Pratt said.
"The political support Obama has in Canada is a lot different than it was 10 years ago with George W. Bush. From that standpoint, I think the timing is not too bad."