"We don't support this Canadian initiative," said Issam Alyamani of Palestine House, an educational and cultural centre in Toronto. "I think that Canada should be more sensitive to the Arab-Palestinian community in Canada.

"The Israeli air force was used to destroy Palestinian houses and it was used against civilians in Gaza and the West Bank.

"I don't think this will help Canada to have a balanced position vis-a-vis the Arab-Israeli conflict."

The military said security will be extra tight this year, but refused to link that to Israeli participation, saying that given the volatile state of the world, close security is natural.

Canadian pilots will join fliers from Belgium, Germany, France, Israel, Britain, the Netherlands, New Zealand, Singapore, Sweden and the United States in the exercises, which stretch over three two-week periods through May and June.

A number of other countries, including Qatar and the United Arab Emirates, are sending observers.

David Rudd, executive director of the Canadian Institute of Strategic Studies said that may help deflect criticism over inviting the Israelis.

"You're inviting the Israelis and also Arab states," he said.

During each of the three exercises, groups of planes will attack targets scattered across the air range, with American pilots acting as defenders.

"The exercise provides critically important air combat training for Canadians and our allied partners, says Col. Duff Sullivan, commander of 4 Wing Cold Lake.

The Cold Lake range spreads across more than 11,000 square kilometres of northern Alberta bush land, an area half the size of Israel. With civilian traffic banned from the area, military pilots have free rein to practise combat skills.

The range contains dozens of mock targets for planes to attack, including airfields, industrial complexes and military installations.

Among aircraft expected to participate are French Mirage F-1s and Mirage 2000Ns, American F-15 Eagles and F-15E Strike Eagles, F-16 Falcons and B-1B Lancers, as well as Canadian CF-18s, and British and German Tornado GR4s.

The Maple Flag concept grew out of the American Vietnam war experience, when it was found that combat training needed to be far more realistic than normal peacetime routine. The Americans began running a series of simulated aerial war games called Red Flag in 1975 and the Canadian military set up the first Maple Flag two years later.