​On Thursday, eight days after Justin Trudeau took office, two CF-18 fighters with laser-guided bombs screamed above the desert city of Sinjar, in northern Iraq.

Below lay a crucial artery for the so-called Islamic State: Highway 47, the main east-west route between ISIS headquarters in Raqqah, Syria, and the ISIS-held city of Mosul, Iraq.

On the ground, Kurdish forces were mounting an assault on the ISIS garrison at Sinjar in a bid to cut its supply line. The Canadian pilots' task was to take out an obstacle to the Kurdish advance: an Islamic State unit dug in to the east of Sinjar at Tal Afar. A second target was an ISIS ammunition store close to Sinjar itself.

Both targets were hit. The counteroffensive worked. With the aid of the Canadian, as well as U.S., pilots, plus Canadian special forces trainers on the ground, the Kurdish forces drove ISIS out of Sinjar. It was hailed as a "liberation" by the remaining Yazidi community, who had been massacred and enslaved by the Islamic State.

But... what happened to Justin Trudeau's pledge to bring the CF-18s home and end their participation in the war on ISIS? And will that pledge survive the massacre in Paris?

1,700 sorties, and still flying

Canada's six warplanes, with an airborne Polaris tanker and two Aurora surveillance planes, arrived at a base in Kuwait just over a year ago, on Oct. 30, 2014. Since then, their contribution to the coalition has been modest but certainly not insignificant.

As of Wednesday — Remembrance Day — Canadian planes had flown 1,731 sorties, according to the Department of National Defence. Of those, 1,109 were combat missions by CF-18 fighters, although they take a cautious approach to releasing their bombs and return without dropping them about two-thirds of the time.

In addition, the C-150 Polaris tanker flew 302 sorties, pouring nearly 8,160 tonnes of jet fuel into coalition aircraft. The two Auroras conducted a further 320 reconnaissance missions, gathering intelligence on ISIS movements.

So they've been busy. Their mission was laid out by the Conservative government in a resolution authorizing it in October 2014. "Unless confronted with strong and direct force, the threat ISIL poses to international peace and security, including to Canadian communities, will continue to grow," it said, using an alternate acronym for ISIS.

Since then, has the threat diminished? The bloodbath in Paris says no.

An easy solution?

Upon his departure from Canada for the G20 summit in Turkey, Justin Trudeau ducked the question of whether he would reconsider his plan to bring the CF-18s home.

"It's too soon to jump to any conclusions," he told reporters at the Ottawa airport.

Previously, though, he has struggled to explain just why he opposed the bombing mission. In an interview on CBC's Power and Politics on June 23, he said the Harper government had failed "miserably" to show why it was the right mission for Canada. Instead, he preferred to enhance humanitarian efforts and to beef up the training mission by Canadian special forces in Iraq.

Trudeau was asked, ​"If you don't want to bomb a group as ghastly as ISIS, when would you ever support real military action as opposed to just training?"

Trudeau dismissed the question.

"That's a nonsensical question and you know that very well," he said. "The Liberal Party has always — and I have always — been supportive of Canada standing up for its values and taking action when necessary."

Trudeau went on, "The question I have for this government, which has failed miserably to do this, is to demonstrate why the best mission for Canada is to participate in a bombing mission."

He also noted that Western military intervention often doesn't end well. "Whether it's Libya or whether it's Iraq, it doesn't necessarily contribute to the kind of outcomes that people would responsibly like to see, and what I've committed to stay away from is the kind of easy solutions in a very complex area that this [Conservative] government has specialized in."

Less than five months later, what now? Is the bombing still just an "easy solution"? Asked repeatedly when the CF-18s will come home, Trudeau has sidestepped the question, saying he will withdraw them sometime, but "responsibly" and in consultation with Canada's allies. He never says when.

PM Trudeau on Paris attacks4:49

Does that mean Trudeau will break his promise? Not necessarily.

Oddly enough, he could keep it by sticking with Stephen Harper's plan. As it stands, the deployment ordered by the Conservative government extends to the end of March 2016. Trudeau, then, could honour his pledge by simply saying they will come home after that.

And after Paris, who will complain that it's not soon enough?

Not packing yet 

Canada's pilots, and 600 supporting troops based in Kuwait, sure don't sound like they're packing up. The mission "continues for the time being under the mandate previously directed by government," says a statement by National Defence spokesman Capt. Kirk Sullivan.

The Armed Forces, Sullivan goes on, "stand ready to implement government of Canada direction when it comes and will liaise with coalition partners to investigate options and transition our military operations in the region."

So we're not going to leave our allies in the lurch. We're integrated into a coalition and we're not going to bail out suddenly.

"We are part of an alliance," the statement concludes, "and we will want to ensure this is done in a co-ordinated manner."

Bugging out — or stepping up?

But it's hard to imagine that the alliance, under U.S. leadership, will scale back its assault on ISIS in the wake of the Paris massacre.

Already, the ranking Democrat on the U.S. House intelligence committee, Rep. Adam Schiff of California, has told the New York Times that, "If this doesn't create in the world a fierce determination to rid ourselves of this scourge, I don't know what will."

Nor does it seem that ISIS is in retreat after the defeat at Sinjar. Rather, it's going global, bragging that worse is to come.

"This attack is the first of the storm," said an Islamic State statement hailing the Paris horror, "and a warning to those who wish to learn. Allahu Akbar!"

Trudeau, then, has an out. Withdrawing the planes now won't look good. But, for at least another four months, he can keep them flying — and still keep a promise that now seems like a liability.

And in March? A lot can change by then.