Canada has shared control of NORAD for more than 45 years; a Canadian general is deputy commander of the command.
"We are looking at what is the position Canada should take within NORAD and other organizations," Mr. Chrétien said in the House. "They are our neighbours, and the defence -- especially in the air -- in the past has been in common."
Ottawa has long expressed opposition to the U.S. plan to develop weaponry capable of shooting incoming ballistic missiles, fearing a new arms race and the weaponization of space.
But the Prime Minister said Canadian opposition is flagging because the U.S. plans for missile defence are less ambitious than when the plan was first dubbed "Star Wars" during the Reagan era.
"The situation is changing.... It is much more limited," Mr. Chrétien said.
"For example, there was extremely strong opposition by the Russians that has diminished since that time. The same thing by the Chinese. So we are looking at the file."
Canada's renewed interest in joining the missile-defence program is being spurred by several looming deadlines in the Bush administration's implementation plans. The United States is working toward deploying initial land-based missile interceptors in September, 2004, and will make crucial decisions about command and control of the plan in the next several months.
Supporters of Canadian participation within the federal government, most notably senior military officers, say Ottawa needs to make a quick decision in order to bring missile defence under the umbrella of NORAD.
Beyond the security implications, supporters of missile defence argue Canadian participation would be an economic boon for Canada's aeronautical industry, allowing companies to benefit from hundreds of millions of dollars in high-technology contracts.
Sources said yesterday it is unlikely Cabinet will make a final decision about opening negotiations with the United States during today's meeting. But Mr. McCallum has said Canada will make its plans known before Parliament rises in June.
The prospect of Canadian participation in missile defence has angered the left wing of the Liberal caucus and Cabinet. Sheila Copps, the Heritage Minister and leadership candidate, has criticized leadership front-runner Paul Martin for supporting missile defence.
Yesterday, John Godfrey, the MP for Don Valley West, said missile defence would "contribute to making the world a more dangerous place" by emboldening the Bush administration in its handling of world military crises.
"If we had missile defence at the present moment, they might well be bolder in dealing with North Korea in a way that would be dangerous for the world because it might involve nuclear weapons," Mr. Godfrey said.
"The Bush doctrine is a doctrine of offence. You can't simply say that national missile defence would protect us from incoming missiles if at the same time it encourages the Americans to be bolder in their defence activities or their foreign policy activities."
He said it is a mistake for the government to embrace missile defence as a way of making amends with the United States for staying out of the war in Iraq.
"It is not a satisfactory answer to say, 'Well, we were right on the war in Iraq, therefore we need to give them a consolation prize,' " Mr. Godfrey said.
Joe Clark, the Conservative leader, accused Mr. Chrétien of preparing to begin secret talks with the United States and demanded Parliament be informed about what role Canada would play in implementation of the missile defence system.
"There has been no information given to Parliament as to what it is the Americans are asking," said Mr. Clark. "We need to know what we are being asked to approve, at least in general terms. That has not happened."
Bill Blaikie, the New Democrat foreign affairs critic, said: "Star Wars isn't going to protect the United States from various forms of terrorism. We don't see the need for it."
salberts@nationalpost.com
Note: From the National Post