Canada is going to war in Iraq.

As expected, the Conservative majority in the House of Commons ensured that the government’s motion to join U.S.-led airstrikes against Islamic State militants passed Tuesday night. The vote was 157-134.

Nearly all the opposition MPs voted against the combat mission, while accusing the government of not providing enough information about Canada’s military commitment. Liberal MP Irwin Cotler abstained.

Six CF-18 fighter-bombers, two CP-140 surveillance planes, one aerial tanker aircraft and 600 personnel are expected to join coalition airstrikes in Iraq for up to six months. The Conservatives’ motion said there would be no troops on the ground.

In a statement after the vote, Prime Minister Stephen Harper said it was “imperative” for Canada to act with its allies to halt the spread of ISIS.

“We do not take this step lightly. The threat posed by ISIL is real,” he said. “If left unchecked this terrorist organization will grow and grow quickly. They have already voiced their local and international terrorist intentions and identified Canada as a potential target.”

Harper was referring to a video message from presumed ISIS fighters, in which they made direct threats against Canada and other countries.

Despite acknowledging the threats and the brutality of ISIS, opposition MPs said they were concerned about a prolonged combat mission since there is no proof that airstrikes will work.

"The Conservatives are plunging Canada into a prolonged war without a credible plan to help victims of ISIL terror,” NDP Leader Thomas Mulcair said in a statement after the vote.

“They have also opened the door to Canadian involvement in Syria's bloody civil war.”

Mulcair said the NDP had laid out a “strong alternative action plan that would significantly increase Canada's humanitarian response to this crisis.”

But the NDP amendment to the government’s motion was defeated Tuesday, despite support from the Liberals.

Earlier Tuesday, NDP’s foreign affairs critic, Paul Dewar, questioned the government on whether the mission will eventually be extended to Syria to fight the ISIS extremists there.

“They’ve left the door open to extending the mission without returning to the House,” he said. “They left questions unanswered about why we would be getting involved in Syria’s civil war.”

Foreign Affairs Minister John Baird said that Canada is “not going to war with Iraq, we’re not going to war with Syria -- we’re going to war with ISIL terrorists.”

“What we have said very clearly is the motion that’s before the House that we will go into Iraq, the democratically elected government has invited us, and we will take real and significant action alongside our colleagues, whether its military support (or) humanitarian support.”

Baird also said that Canada will work with its allies, such as the U.K., the U.S. and France to determine “whether we’ve been successful in stopping the growing crisis.”

Just after he abstained from the vote, Cotler issued a statement saying that the government motion lacked “clarity.” He also said he was “deeply disturbed” by the possibility that Canada “would require the approval of the criminal Assad regime to carry out operations in Syria.”

First mission since Libya

The White House press secretary issued a statement late Tuesday welcoming Canada’s contribution to the fight against ISIS.

“With these deployments, Canada demonstrates its continued leadership and resolve in addressing the urgent and critical security challenges that threaten Canada, its people, and the broader international community,” the statement said.

“Canadians and Americans have fought alongside each other in several major conflicts over the past century, and we are grateful for Canada’s further contribution against terrorism.”

This will be Canada’s first combat mission since the 2011 NATO-led airstrikes in Libya. That mission was originally supposed to last 90 days, but was extended to seven months, until the death of Libyan dictator Moammar Gadhafi.

Canada sent seven fighter jets to Libya, in addition to other naval and air equipment, and deployed more than 650 Canadian Forces personnel at the mission's peak. Canada’s contribution cost a total of $347 million.

Retired Lt.-Gen. Charles Bouchard, who led the Libyan mission, told CTV’s Power Play Tuesday that no two combat missions are alike, but some basic principles always apply.

He said “air power” alone won’t destroy ISIS in Iraq, but coalition airstrikes have already had an impact, limiting the militants’ movements in the region.

“There is an array of potential targets that can be engaged with air power to have an effect,” he said.

During the mission in Libya, NATO forces were always aware of potential civilian casualties, Bouchard said.

“If you’re not sure, or if you have any doubts civilian casualties will take place, go home. Do not drop bombs,” he said. “I’d rather come back to fight another day and make sure we do not lose that moral high ground.”

Bouchard said it’s not only important to understand the ISIS targets, but also the politics and the culture involved.

“We have to consider that this is more than a military operation,” he said. “You cannot stop the political dialogue, the diplomatic dialogue that continues with that.”

With files from Andrea Janus and The Canadian Press