Two of Canada's most experienced former diplomats believe the G8 is still a powerful tool, and Canada's involvement gives the nation a level of global credibility it wouldn't have otherwise.

The Group of Eight industrialized, democratic nations has faced recent criticism that it is irrelevant, ineffective and outdated.

That's simply not the case, said Paul Heinbecker, of the Centre for International Governance Innovation and a former Canadian ambassador to Germany.

"One of the things people need to understand is that while there has been a lot of cynicism about this G8...in fact it's been a pretty effective organization," Heinbecker told CTV's Question Period in an interview that aired on Sunday.

"The terrorism cooperation we're seeing now was basically born there at the G8, and when the Kosovo war was ended it was ended because of the G8 ... the raising of $50 billion in aid for Africa, that came out of the G8 -- so the G8 can deliver, though it has some problems."

Canada's place at the table is now more important than ever, he said.

"It's in organizations like the G8 when the prime minister is sitting around the table with the most important leaders in the world, talking about the most important questions in the world that we build our credibility with the others and where he develops a more profound understanding of the issues and the people and he enhances his capacity to deal with all of them," Heinbecker said.

Gordon Smith, director of the Centre for Global Studies at the University of Victoria, agreed the G8 is still vital, and Canada's membership should be valued.

"I think that if we were not a member of the G8 we would find out own stature in the world and our ablility to speak out on issues and try to make things happen, like bans on anti-personnel mines and the creation of the international criminal court, significantly more difficult. In other words our role in the G8 significantly enhances our role in the world," Smith said.

Both former diplomats agree Canada has gained credibility at the G8 as it has bolstered its military and commitment to Afghanistan, and as it has gained stature as a global energy supplier.

And they agree the organization still has formidable clout.

"When the G8 decides they want to do something, that sets in motion a lot of wheels and capitals, and those wheels work towards the next meeting," Smith said.

"So the fact the G8 takes place pushes a lot of work with an agenda, a timetable, that wouldn't otherwise occur."

Although the group is still officially made up of eight members -- Canada, the U.S., Germany, Russia, Italy, France, Japan and the U.K. -- the organization has become a "defacto G13," with the addition of India, South Africa, Mexico, China and Brazil, which will be attending this wekend's meetings.

"The G-what is the question," said Heinbecker, noting that the group is bound to officially expand in the coming years, and may need to become more representative of the world, perhaps by including a Muslim nation.

However, expanding too fast, and too much, could hurt the G8 in the long run.

"The advantage of keeping numbers lower is it permits the kind of freewheeling discussion that takes place at these meetings to occur." Smith said.

"But I think 13 or 14 would significantly increase the legitimacy of, and therefore the effectiveness of the G8."

The former diplomats predicted the leaders will discuss the mounting issues of the day, including tensions in the Middle East, Iran's nuclear ambitions and North Korea's recent testing of long range of rockets.

But significant time will also be allocated to the issues Russia, as host, has put forward. They include education, infectious diseases and energy security.