Three terror bombings in Mumbai immediately turned suspicion on groups that have been sponsored by Pakistan.
There's no evidence yet of who is responsible for the blasts that killed 21, and Pakistan's government quickly condemned the attacks. But that's unlikely to quell suspicions in India.
It could quickly fuel a cycle of distrust in the region that Canada has been caught up in before - in Afghanistan.
Even after combat in Kandahar, Canada, like the rest of the world, has an interest in seeing that this dangerous dynamic doesn't heat up. Pakistan and its uncontrolled army intelligence agency, which has already frustrated the United States, is at the centre of the question.
Immigration Minister Jason Kenney said Canada supports India in its fight against terrorists. "We've seen a similar attack in a similar way not long ago," he said.
He was referring to the 2008 attacks in Mumbai that killed 164, and were traced to Lashkar-e-Taiba, a militant Pakistan-based group backed by elements of Pakistan's intelligence agency. They, and the homegrown Indian Mujahedeen, who also are believed to have been helped by the Inter-Services Intelligence agency, are immediate suspects in India this time.
An immediate danger is that the attacks could derail India-Pakistan talks aimed at cooling tensions. The bombings may have, in fact, been a spoiler attempt, said Daniel Markey, senior fellow for India and Pakistan at the Council on Foreign Relations in Washington.
Tensions between India and Pakistan have a larger effect in the region. Pakistan, especially its powerful army, sees India as its overriding adversary and has sponsored groups such as the LeT as strategic assets. It backed the Taliban in Afghanistan in a proxy battle with India for influence.
That doesn't seem to be the policy of Pakistan's civilian government now, but it isn't really in control. The army is dominant, and inside the army, the intelligence service, the ISI, is powerful.
It's hard to tell how much of the army or the government supports terror groups or insurgents. "Parts of the ISI very clearly still support LeT. It's dangerous to go beyond that," Mr. Markey added.
Many Canadian officials have held the same view about support for the Afghan Taliban. Former Canadian ambassador to Afghanistan Chris Alexander, now a Conservative MP, last year accused Pakistan's army of "complicity."
Some wanted Ottawa to out that role with criticism, others wanted to try to change it. Carleton University professor Eliot Tepper argues that India, Pakistan and Afghanistan should be treated as one "security complex" and Canada should adopt a broader aid and trade policy to strengthen Pakistan's civilian elements.
There was an international wave to do that two years ago, led by late U.S. envoy Richard Holbrooke. Pushing India to reduce troops on the border would make Pakistan feel more secure and would stop support for insurgents, it was argued. But Mr. Markey said that ran into a "buzzsaw" with India, which wouldn't make security compromises that, it argued, wouldn't change Pakistan's behaviour anyway.
Now the United States is frustrated with engagement in Pakistan. Osama bin Laden was found there, and then-CIA chief Leon Panetta reportedly confronted the ISI over leaks that allowed insurgents to slip away. Since then, Washington has decided to withhold $800-million in military aid to Islamabad.
That alone won't change Pakistan, Mr. Markey argued; another step is to quietly convince others with influence, such as China and Saudi Arabia, that the "increasingly unmanageable" ISI must be cleaned up, for their interests, too.
Canadian criticism won't move Pakistan, either. But Canada does have a smaller part: Encouraging India to keep talks going, looking for ways to foster civilian government in Pakistan and pressing the world to see its intelligence agency as a global problem.
Campbell Clark writes about foreign affairs from Ottawa.