The federal government has shown wisdom in appointing former Supreme Court justice Frank Iacobucci to review its Afghan file. The government clearly needs some advice to help it deal with what is a tricky question, both in principle and politically.

The opposition parties are united in their desire to learn more about what the Conservative government knew about the risk that Afghan prisoners detained by Canadian troops might be tortured if they were turned over to Afghanistan’s intelligence agents.

The opposition’s desire is fuelled by the testimony of witnesses who appeared before a Commons committee last fall who said the prisoners were turned over even though the risks were well known in Afghanistan at the time.

Because the government has only a minority of the seats in the Commons, the opposition parties were able to combine their votes last year to order the government to release the documents outlining what it knew about the risk of torture.

The government, so far, has refused to comply with the order. It argues that the documents are sensitive and that releasing them would jeopardize national security.

This is a complex dispute because there are two worthy principles conflicting. The government does have a responsibility to protect national security generally and the Canadian Forces in particular. If the release of these documents would compromise the Canadian mission in Afghanistan or assist the Taliban militarily, then the government would have good reason to try to withhold them.

Similarly, the government also has a responsibility to the House of Commons. The government exists only because the Commons wants it to exist. Ultimately, Parliament is supreme. The government is responsible to Parliament, not the other way around. Parliament has the power to overrule a government. It can do so by voting no confidence in a government — if it is prepared to see the government fall.

It is true that Prime Minister Stephen Harper has been known to avoid a confidence vote by proroguing Parliament. Prime ministers may delay confidence votes, but they cannot avoid them indefinitely.

By agreeing to review the Afghan file, Iacobucci may have given the government and the Commons a chance to take a second, calmer look at the issues. Iacobucci has an exceptional reputation. He is a former law professor and deputy justice minister. He sat on the Supreme Court from 1991 to 2005. He was also chair of the board of Torstar Corp.

If Iacobucci concludes that the government should release all or even most of the documents, the government would have a hard time withholding them. But if he thinks some of this information is too sensitive for public distribution, the opposition might not want to continue arguing with the vigour it has until now.

Iacobucci’s task now is to separate principle from the political partisanship.