"It is at times of tension like these," Prime Minister Justin Trudeau said Saturday, after Iran admitted that one of its missiles had shot down Ukraine International Airlines Flight PS752, "that tragedies like this crash can happen."

Before concluding his prepared remarks, Trudeau also said that Iran must take "full responsibility" for the tragedy.

It's possible, in a nuanced world, for those ideas to co-exist. But these are difficult days for nuance.

From the moment it became clear that the aircraft had been shot out of the sky, there have been questions about whether U.S. President Donald Trump, in ordering the targeted killing of Iranian general Qasem Soleimani, shares some of the responsibility for the tragedy of PS752. Trudeau has been pursued by those questions.

As tempting as it might be to point fingers, a debate over blame right now might risk obscuring a larger lesson about international conflict.

The most prominent Canadian blaming Trump right now is the chief executive officer of Maple Leaf Foods, Michael McCain. He tweeted on Sunday about the "irresponsible, dangerous, ill-conceived behaviour" of "a narcissist in Washington." American commentator David Frum had made a similar argument days earlier.

..A narcissist in Washington tears world accomplishments apart; destabilizes region. US now unwelcomed everywhere in the area including Iraq; tensions escalated to feverish pitch. Taking out despicable military leader terrorist? There are a hundred like him, standing next in line —@MapleLeafFoods

Asked about McCain's comments on Monday, Trudeau stopped short of explicitly pointing at any specific action or actor.

"I think if there were no tensions, if there was no escalation recently in the region, those Canadians would be right now home with their families," he told Global National. "This is something that happens when you have conflict and ... war. Innocents bear the brunt of it. And it is a reminder why all of us need to work so hard on de-escalation, on moving forward to reduce tensions and find a pathway that doesn't involve further conflict and killing."

The prime minister's reference to recent escalation might sound like a comment on the targeted killing of Soleimani. But Soleimani's death happened after Iran's associates had acted to escalate the conflict with the United States — with an airstrike that killed an American contractor in December and with the crowd of protesters who stormed the American embassy in Baghdad.

A crisis with no single catalyst

Trudeau also has pointed out that the conflict in the region is not a recent development. "The reality is there have been significant tensions in that region for a long time," the prime minister said Saturday.

Politically, it might be difficult for any Western leader to single out the United States for blame. Practically, it also would be difficult to identify an indisputable starting point for the sequence of events that led to the deaths of 57 Canadian citizens last week.

If Soleimani hadn't been killed by the Americans, Iranian defence forces might not have been primed to shoot a plane out of the sky. But a long chain of actions and reactions in the region, spanning decades, led up to Soleimani's demise.

"Assigning blame publicly is an extremely political thing," said Thomas Juneau, a professor of international affairs at the University of Ottawa and a former analyst at the Department of National Defence.

Iranians march with a banner bearing an portrait of Iranian Revolutionary Guards Major General Qassem Soleimani during an anti-U.S. demonstration in Tehran on January 3, 2020. (Atta Kenare/AFP via Getty Images)

Had Trump chosen not to order Soleimani's death, he said, PS752 probably wouldn't have been shot down. "But why did the U.S. kill Soleimani? Because Iran launched its Shia militias in Iraq to attack the American embassy in Baghdad.

"You could move backwards until 1979 and the [Iranian] revolution. If you really want to have a bunch of academics in the room, they will go back to 1953, when the U.S. supported a coup in Iran. This is a very difficult exercise."

If you see Trump's order as rash and reckless, you're likely all the more tempted to blame him for everything that happened after. If you view Soleimani's death as justified and ultimately productive, you might be less inclined to connect it with what followed.

While the post-crash investigation may produce details that complicate our understanding of what led to this disaster, it ultimately could be difficult to completely divorce the American action from the wider pattern of regional escalation.

But one thing, at least, is indisputable: an Iranian rocket killed 176 civilians, many of them Canadians. Iran is responsible for that. Iran must account for it. And Iran almost certainly will be called on to provide compensation for the families of those who died.

Part of the wreckage of Malaysia Airlines Flight MH17 near the village of Hrabove, Donetsk region, on July 20, 2014. (Maxim Zmeyev/Reuters)

Trudeau's comments about what can happen to non-combatants at a time of heightened political tension and conflict echo the words offered by U.S. President Barack Obama in 2014 after a Russian missile brought down Malaysia Airlines Flight 17 (MH17) over Ukraine.

"Now is, I think, a sombre and appropriate time for all of us to step back and take a hard look at what has happened," Obama said, long before anyone had reason to blame Donald Trump for much of anything. "Violence and conflict inevitably lead to unforeseen consequences."

Ten civilian flights shot down since Second World War

As Stephen Saideman, a professor at Carleton University's Paterson School of International Affairs, noted last week, PS752 and MH17 are just two of at least ten civilian flights that have been shot down since the end of the Second World War. Most of those disasters, Saideman argued, occurred outside of a climate of open warfare, when tensions between two or more countries were running especially high.

Given how much of the last 80 years nations have spent in one state of armed tension or another, it might be argued that tragedies like PS752 are effectively rare. But the innocent lives lost and damaged by the destruction of PS752 can also be viewed in the wider context of the unforeseen, but inevitable, events that surround any military conflict.

"When conflict comes, when situations escalate, there are collateral victims, there is collateral damage. In this case, remember that most of the collateral damage is innocent Iraqi civilians, innocent Iranian civilians. But in this case, it happened by a string of very unlucky coincides that it included 57 Canadians," Juneau said.

"When states go to war, academics will tell you that there is a tendency to neglect, in the calculus leading to the decision, the costs of war. And the costs of war are extremely unpredictable. They are unforeseeable in many ways ... We should foresee that there will be unforeseen consequences."

That lesson might risk getting lost in the back-and-forth over Trump's actions and responsibility.

Speaking at a memorial for victims of PS752 in Edmonton on Sunday, Alberta Premier Jason Kenney — a former Conservative defence minister — offered an assessment that lines up with the words of both Trudeau and Obama.

"Whether their lives were taken by incompetence, by accident, or by design, we know everyone aboard that plane were victims of a chain of actions rooted in the all-too-human failure to resolve conflicts peacefully," he said.

Among the consequences of this dark moment in Canadian and world history might be a sharper understanding of the risks inherent in any nation's decision to go to war — and the suffering that inevitably reaches well beyond those who do the actual fighting.