A summer of sabre-rattling with North Korea appears to have put a dent in the Liberal resolve to keep Canada out of the U.S. ballistic missile shield.

A Commons committee held a special meeting in Ottawa on Tuesday looking for answers on what sort of military preparations have been made by the Trudeau government in the event the crisis over missiles and nuclear testing by the regime of Kim Jong-un spirals out of control.

But the discussion quickly fell into a familiar political refrain.

The idea that North Korea has a nuclear-tipped missile that might be capable of reaching North America has intensified the debate over whether Canada should join the U.S. anti-ballistic missile defence program.

The Liberal government, in its recent defence policy, made a conscious choice to uphold a 2005 decision that kept Canada outside of the largely unproven, high-tech interceptor system. Instead, the policy proposed to find ways to mitigate the threat of ballistic missiles through the modernization of the air defence command NORAD and by improving the chain of radar stations known as the North Warning System, which was not intended to track high-flying, incoming missiles.

The all-party Commons defence committee has previously endorsed the idea of joining missile defence. It and a similar recommendation by the Senate defence committee were ignored.

A new situation, a new threat

Even though the ink is barely dry on the defence policy, there are some suggesting the upcoming parliamentary hearings on North Korea, agreed to on Tuesday, would provide a chance to think about lifting the prohibition.

"North Korea has been toying with missiles, I mean, ballistic missile defence would be something that would most definitely come up," said Liberal MP Mark Gerretsen. "What I can tell you is that, personally, we do need to start to look at what Canada's role will be in that."

Gerretsen emphasized he was not speaking for the government, only as an individual member of the defence committee.

He said a lot has changed since the Liberal government of former prime minister Paul Martin chose not to take part.

Tories have no clear position

Ballistic missile defence is one of those radioactive political issues in Canada.

Not only did the Liberals back away from it, but so did Stephen Harper's government.

It was the Conservatives who were responsible for calling the emergency committee meeting during the summer recess.

They arrived, however, without a clear position on whether they support joining the missile shield or not.  

It is something that will be decided at the party's upcoming policy convention, said defence critic James Bezan. He argued that threat from North Korea really hadn't evolved until the regime in Pyongyang first tested its latest long-range missile on July 4.

"You've got to remember the history behind that discussion, the wounds that were created because of the decision by Paul Martin back in 2005, and things didn't change until this summer," Bezan said. "So from this point forward, everyone is looking at how we can best work with the United States. How we can work through NORAD in dealing with this new threat."

'No viable military option'

New Democrats served notice on Tuesday that they would once again fight tooth and nail against any proposal to join a system they claim is expensive and doesn't work.

"We have other priorities," said Hélène Laverdière, the NDP foreign affairs critic, who added that the solution to the current standoff is not a military one.

"The basic answer in all crises of that type is diplomacy."

The diplomatic question, however, is: What does North Korea want?

In the past the international community has bargained repeatedly with Pyongyang offering incentives, even food shipments, for it to give up its nuclear program.

It hasn't worked.

One expert insists there is still room for optimism.

"I think the fact that it has failed in the past is not a good enough reason for us to give up and remain cynical about the situation in North Korea," said Tina Park, the executive director of the Toronto-based Canadian Centre for the Responsibility to Protect.

"The small size of the Korean peninsula is such that there is no viable surgical option when it comes to military confrontation. It is a very small country on both sides. And any attack on North Korea or South Korea will have ramifications across the 38th parallel. So, the actual likelihood of a war breaking out remains low."