Peter MacKay in U.S. meeting with Chuck Hagel, John McCain

Sen. John McCain, R-Ariz., shakes hands with Canadian Defense Minister Peter MacKay during a news conference at the Canadian embassy in Washington, Tuesday, June 18, 2013. (AP / Manuel Balce Ceneta)

WASHINGTON -- Sen. John McCain urged the world on Tuesday to learn from past mistakes as it passively observes Syria's bloody civil war while Canada's defence minister, Peter MacKay, stood by the Canadian government's decision against arming the Syrian rebels.

"There's an old line about those who refuse to learn the lessons of history are doomed to repeat them," McCain told reporters at the Canadian embassy in the U.S. capital.

The onetime Republican presidential candidate, a fierce advocate for U.S. military intervention in Syria for the past two years, made reference to the origins of various global conflicts, including the Second World War, and how dramatically they cascaded when the rest of the world did nothing to intervene.

As MacKay looked on, the Arizona senator noted the Syrian turmoil is "evolving into a regional conflict" as Lebanon becomes destabilized and the Russians and Iranians boost their military might.

"I can assure you of one thing, that unless we take some decisive action, this regional conflict will spread, this conflagration will spread throughout the Middle East while we have watched this unfair fight take place with the slaughter or some 93,000 people," he said.

MacKay, on the other hand, said the Canadian government is reluctant to arm the rebels, despite President Barack Obama's recent announcement that the U.S. government will begin sending small arms to the Syrian rebels locked in a two-year conflict with President Bashar al-Assad's regime.

Prime Minister Stephen Harper said recently that Canada will continue to send humanitarian aid to Syrian refugees, but has no plans to send arms.

"We've expressed reservations," said MacKay, who called the Syrian conflict "a complex situation in the extreme."

"We want to know who we are arming. We need to have, I believe, a greater sense of understanding where those weapons will arrive. And to that extent, we are again sharing intelligence, working with our closest allies, to achieve that greater level of comfort."

McCain was asked if Canada should take on a bigger role, including helping to enforce a no-fly zone over Syria in order to help the rebels, but politely dodged direct criticism.

"I can't tell the Canadian government and people what they should decide, I can't even urge them to, because I know that the American people and the Canadian people are very reluctant to get involved, as Iraq and Afghanistan (have) shown .... I value everything the Canadian people have done in the defence of freedom throughout the world, so I will leave that decision up to them."

But he also urged those arguing against military intervention in Syria to look not just at Iraq and Afghanistan, but other former troublespots, including Bosnia and Kosovo. Canadians stepped in during both those disputes.

"We, with air power, went in and stopped genocide from taking place in the very heart of Europe," he said. "So everybody looks at the Afghanistan and Iraq examples, but there are other examples."

McCain was at the embassy on Tuesday to receive an honorary doctorate in military science from the Royal Military College of Canada. A smiling McCain was seen in a swank meeting room on the embassy's top floor donning the college's red-and-white robe, although MacKay's office kept the media out of the ceremony.

The senator was honoured for his "dedication to our countries' bilateral relationship and to his extensive work in promoting international security," MacKay's office said.

At the embassy, the defence minister called McCain "a great friend to Canada, truly one of the great men of our generation."

Later in the day, MacKay met at the Pentagon with Chuck Hagel, the new U.S. defence secretary. The men discussed the growing influence of China and Canadian and American concerns about cyber-security, as well as NORAD and the reorganization of NATO.

MacKay started his day by delivering the keynote address to a meeting of the of the Inter-American Defense Board, an international organization devoted to defence and security issues, and the Organization of American States.

He told the gathering that Canada planned to continue to send warships and military aircraft to support anti-drug operations in the Caribbean and off the Pacific coast of Central America as part of the Conservative government's efforts to fight multi-billion-dollar illicit drug trafficking in the Americas.

"It's an activity in which the men and women of the Canadian Forces are routinely working in partnership with both military and law enforcement personnel from many of your countries," he said.

"Challenges like drug trafficking, trans-national criminal organizations and natural disasters affect us all. These threats are complex and they don't respect borders. So no matter what their causes or sources may be, the fact of the matter is that they affect all of us, in every corner of the Americas -- including Canada. They require co-operative responses."