A logo of China National Offshore Oil Corp (CNOOC) is seen at the top of its headquarters in Beijing November 14, 2012. REUTERS/Petar Kujundzic

Prime Minister Stephen Harper just made a clear, wise decision on foreign governments buying our natural resources. Or so he claims. The problem is, we don't really know what he did or why, and what we do know isn't reassuring.

Yes, he approved the Chinese state firm CNOOC's $15.1-billion takeover of Nexen, and Malaysia's Petronas $5.2-billion bid for Progress Energy, while saying from now on such purchases of oilsands firms would only be allowed under an "exceptional circumstance." But we have no idea what that term means.