CALGARY — When Prime Minister Stephen Harper approved a massive foreign takeover of a major Canadian oil company and laid out rules for similar deals in the future, the decision might have answered one question, but it raised a host of new issues.

Last month, the Harper government gave its blessing to the $15-billion sale of Nexen Inc., a large Calgary-based oil and gas producer active around the world. The federal government also said that, in the future, similar takeover bids initiated by state-owned enterprises (SOEs) for Canadian oilsands businesses will be approved only "in exceptional circumstances."

Industry Canada will also cast a wary eye at the extent to which any foreign government is likely to exercise influence over a state-owned firm acquiring a Canadian business, no matter what the industry.

In taking this compromise approach — saying "yes" to the deal at hand, but "not likely" to future oilsands bids — Ottawa moved to mute the criticism it likely would have received if it had either nixed the deal between China National Offshore Oil Corp. (CNOOC) and Nexen, or left the floodgates wide open to future entreaties for Canada's bitumen.

"We've drawn a very clear line," insisted Jason Kenney, one of Harper's most senior Alberta cabinet ministers.

"If you are a state-owned enterprise that's tightly controlled by a foreign government, and you're going to have a disproportionate influence in a Canadian industry, there's little or no chance that you'll get approval in Canada. You probably shouldn't even bother making the acquisition here."

But as foreign investors, provincial governments and Canadians try to make sense of the new guidelines, academics say it's not as clear-cut as it might seem.

"I read the prohibition more as an instrument of flexibility for the government rather than a hard-and-fast rule," said Yuen Pau Woo, president of the Vancouver-based Asia Pacific Foundation of Canada.

Woo said given that CNOOC and Petronas — the Malaysian national oil and gas company that bought Canada's Progress Energy Resources Corp. last month — were able to pass Ottawa's "net benefit" test, it's likely other SOEs could emulate their examples.

"There is a track record now."

He noted Canada's natural gas industry is being treated differently than the oilsands and Ottawa has left the door open to Chinese firms taking over gas producers, now struggling with the challenge of stubbornly low prices.

Woo said if the oilsands industry falls on similarly hard times in the years ahead, the government could find itself revising its new rule on SOEs.

"We should not imagine this to be a permanent situation, but rather one that responds to current market conditions," Woo said. "Exceptional circumstances may not be that exceptional."

But Gordon Houlden, director of the University of Alberta's China Institute, doesn't think the Harper government is going to soon move away from its policy of treating the oilsands as exceptional, because of significant public resistance to major Chinese investment in significant non-renewable resources.

"If you were China National Petroleum Corporation (CNPC) or Sinopec waiting in the wings to make a similar oilsands purchase ... that won't work."

Yet, Houlden said SOEs are massive, growing players in global oil and gas markets, and are still going to want to invest in Canada's bitumen resources, whether it be through joint ventures or by taking a minority stake in producers. He noted the oilsands may need more than a trillion dollars worth of investment in the years ahead as production climbs.

Houlden, a former Canadian diplomat in China, acknowledges the national security concerns of many Canadians regarding Chinese SOEs, but says they are too big a factor to ignore.

"Where are we going to get that money? The biggest pools of patient capital that thinks in decades, not in just quarters or a couple of years, are in the SOEs."

Some critics have questioned what makes the oilsands a special case, but Natural Resources Minister Joe Oliver insists the oilsands are exceptional for a number of reasons, including the fact about 80 per cent of the world's oil reserves are already controlled by governments or state-owned enterprises, so it's a good idea to keep the remaining "free enterprise oil" relatively free.

"The other issue is the strategic importance of this resource to Canada," Oliver said. "It represents enormous economic potential."

At the Canadian Association of Petroleum Producers, the industry's main lobbying group, vice-president Greg Stringham also said he is constantly asked what makes the oilsands so special, and why aren't shale gas or tight oil companies included in the protection from SOE ownership?

He argues that, while the rest of the world has similar oil and gas reserves to Canada in some respects, "the oilsands are different, and it is the third-largest resource in the world."

Under the new rules announced by Harper, state-owned enterprises will also receive more scrutiny for every Canadian deal they make — whether it involves the oilsands or not.

Stephen Clarkson, a professor of political economy at the University of Toronto, said the government's decisions regarding SOEs under the Investment Canada Act are likely to be influenced by how Ottawa perceives the regime that controls the companies.

Single-party Chinese firms will likely be judged more harshly compared to other state-owned companies with oilsands stakes, Clarkson said.

"No one's really batting an eye at Norway's Statoil," he said.

While the Harper government's recent reluctance to allow SOEs into the Canadian economy in a major way could have germinated with an ideological opposition to public ownership, Clarkson said it has likely evolved into a concern that Canada's markets are open, while generally China is closed.

The deep pockets of state-owned enterprises are another area of concern as they face off against companies operating in a competitive environment. "They can presumably operate at a loss if it's in the government's interest for them to get a foothold," Clarkson added.

Both Woo and Houlden believe the level of foreign SOE investment in Canada — whether it's in the oilsands or other industries — will be a subject of intense debate in the years ahead.

The Harper government "has left open — constructively, I think — the possibility for a calm and sober discussion on exactly what it is we fear about foreign SOE investment in this country," Woo said.

Houlden also believes there's an opportunity for a broader public policy debate about the role of SOEs in Canada's economy — a discussion that must include affected provinces such as Alberta.

"China is a brand-new thing and people have to get used to a new player," Houlden said. "But the Chinese economy is not going to go away. It's getting bigger every day."