Canada’s Conservative government is once again evoking the phrase "ethical oil", suggesting that U.S. approval of TransCanada’s Keystone XL pipeline will help combat international tyranny and repression.

"Our oil sands represent a sustainable, ethical and responsible source of oil for the United States," International Trade Minister Ed Fast told the Globe and Mail during a recent visit to Washington, DC.

Much more so, he argued, than "oil from places like Venezuela and Nigeria and Saudi Arabia."

The Minister’s remarks came only one day after President Barack Obama delivered a major climate change speech in which he declared the climate impacts of Keystone XL "will be absolutely critical to deciding whether this project goes forward."

That’s no problem either, Fast reportedly said, arguing that oil sands crude is greener than – as well as ethically superior to – other oil sources.

After reaching a pinnacle of popularity in 2011, the term "ethical oil" has slowly departed from Canada’s political discourse.

It returned briefly this May, when former U.S. vice-president Al Gore argued that, "There’s no such thing as ethical oil…There’s only dirty oil and dirtier oil."

Yet Fast’s recent remarks suggest the Conservative government still considers its promotion of the oil sands to be aiding the fight against global injustice -- a profoundly "ethical" mission.

Geoff Dembicki reports on energy and climate change for The Tyee.