WHEN Stephen Harper, Canada’s prime minister, sought parliament’s permission in October to supply troops and aircraft to the coalition fighting Islamic State (IS), he said that the mission would last six months and that Canada would not launch strikes within Syria without the support of that country’s government. On March 24th he altered both conditions, asking parliament to approve a longer mission and bombing of Syrian targets regardless of whether President Bashar Assad agreed. This is necessary, says the Conservative prime minister, because IS is at its strongest in Syria.

The proposal is likely to be popular in Canada, where two soldiers died in terrorist attacks last October. It did not persuade the left-leaning New Democratic Party (NDP) or the centrist Liberals. Their leaders complained that the government is putting Canadians in harm’s way without a clear objective or exit strategy. Thomas Mulcair, the NDP’s leader, accused Mr Harper of appearing to join forces with Mr Assad, “a brutal dictator and war criminal”, even though the bombing would happen without the Syrian leader’s approval. By attacking IS in Syria, Canada will be helping Mr Assad in his fight against that group and others in the country’s civil war. Apart from the United States, no NATO member has bombed targets inside Syria, although Jordan and the United Arab Emirates have done so.

Mr Harper can shrug off such objections, at least for now. His Conservatives have a majority in both houses of parliament. Fighting terrorists enhances the Conservatives’ tough-guy image and distracts from the current weakness of the economy. With a general election scheduled for October, that is helpful. It also fits neatly with the prime minister’s pro-Israel foreign policy. He was one of the first foreign leaders to congratulate Binyamin Netanyahu, Israel’s prime minister, after his surprise election victory (while reaffirming Canada’s support for a Palestinian state).

Still, Mr Harper is taking a risk. Like Canada’s participation in the war in Afghanistan, which dragged on for 12 years and involved 3,000 troops at its height, the fight against IS threatens to outgrow its modest beginnings. What started in September as a 30-day commitment to advise Iraq’s government became a six-month mission to provide advice and assistance. It employs 600 troops, six fighter jets and aircraft for surveillance, refueling and airlift. As of March 21st, the jets have flown 428 sorties and made 53 of the coalition’s 1,631 air strikes in Iraq. The mission will now be extended for another year. The objective set forth by Mr Harper--“to continue to degrade the capabilities” of IS--is sufficiently vague to leave room for future extensions.

The opposition says he has not been frank about what the troops are actually doing. Roughly 70 are special forces and the rest are air crew and support staff. Theirs is a non-combat mission, the government insists. Mr Mulcair calls that claim ludicrous. The special forces accompany Iraqi troops to the front lines and call in air strikes. They have been involved in firefights, provoked when Canadians were fired upon, say officials. One Canadian soldier died in March; the government says he was killed by friendly fire.

When the troops finally came home from Afghanistan, Canadians were split down the middle on whether the war had been worth it. Mr Harper will be hoping for a more favourable verdict on his fight against IS.