Often hijacked by international crises, the G8 summit has once again been waylaid — this time, by the slaughter in Syria.

Officially, the British host, Prime Minister David Cameron, had wanted the summit to focus on tax evasion and transparency in international trade. But even Cameron now says that Syria will be the dominant issue when the leaders gather in Northern Ireland on Monday and Tuesday.

The growing evidence that the regime of Syrian President Bashar al-Assad has employed chemical weapons against rebel forces, followed by the U.S. decision to give those rebels small arms, have concentrated minds not just on the question of where this will lead, but on the split in the G8.

For months, the Western powers have stood resolutely on the sidelines — citing the lack of any consensus for intervention. Russian President Vladimir Putin has helped mightily to ensure that such a consensus does not emerge. Putin has resisted any imposition of sanctions on his Syrian ally — and it's Russia that made what used to be the G7 into the G8, having been added in a bid to bring it into the orbit of the Western liberal democracies.

Policy on Syria

Now, those democracies are scrambling to find some plausible course of action in Syria, whether Putin likes it or not. U.S. President Barack Obama held a video conference on Syria on Friday evening with just four of the G8 leaders: British Prime Minister David Cameron, German Chancellor Angela Merkel, French President Francois Hollande and Italian Prime Minister Enrico Letta.

Prime Minister Stephen Harper, who's been on a European tour on his way to the summit, was not involved in the video call. However, he has accepted the U.S. conclusion about the use of chemical weapons.

"We share the view of our allies, I think, based on the evidence before us, that there have been uses of chemical weapons in Syria by the regime," Harper said at a joint press conference on Thursday with Hollande.

But, speaking Wednesday to the British Parliament, Harper came down firmly against arming the rebels — many of whom are Sunni Islamist forces, fighting to displace a regime backed by Iran and its client Shia militia in Lebanon, Hezbollah.

"The extremist, sectarian nature of much of the opposition cannot be ignored or wished away," said Harper, adding that "Syria cannot be allowed to become another safe haven for the hydra-heads of terrorism."

Now, Harper may have to re-align his policy with those of allies like the U.S., Britain and France, who are all moving away from the sidelines. But, even if he does, it does not seem likely that the Russians will move with them.

Speaking to U.S. Secretary of State John Kerry on Friday, Russian foreign minister Sergey Lavrov dismissed U.S. claims that Assad's forces have used chemical weapons such as the nerve gas, sarin.

"The accusations put forth by the United States to Damascus about the use of chemical weapons are not supported by trustworthy facts," Lavrov said, warning that U.S. involvement would be "fraught with escalation in the region."

Free trade stalled

All of this has overshadowed Harper's attempt to coax European leaders to finally sign a long-promised free trade agreement with Canada. In London, Prime Minister Cameron was supportive. But differences remain on matters of government procurement, patent protection for pharmaceuticals and beef.

Finance Minister Jim Flaherty and Prime Minister Stephen Harper are treated to some Irish hospitality after arriving for the G8 summit. (Irish Foreign Ministry)

Both France and Ireland remain skeptical about Canadian demands for greater duty-free access to the European market for Canadian beef and pork.

Harper met Sunday in Dublin with Irish Prime Minister Enda Kenny and Deputy Prime Minister Eamon Gilmore. But, in trade talks, a little public relations never hurts. A notorious non-drinker, Harper nevertheless pleased his Irish hosts by posing for pictures under a sign saying, "Guinness is good for you" during a tour of the famous Guinness brewery.

Harper even managed to swallow a little of the heady brew for the cameras.