Before the meeting, Mr. Trudeau stopped by Latvia, signaling that what countries actually do for NATO is what counts. While there, he announced that Canada would extend its NATO mission in that country by another four years and increase the number of troops it has stationed there to 540 from 455 to discourage any Russian incursion. Then while in Brussels, Mr. Trudeau said that up to 250 Canadian troops and four military helicopters would lead a new NATO training mission this fall for security forces in Iraq.

Those announcements followed a commitment by Canada to send 250 troops to support a dangerous and often deadly United Nations peacekeeping mission in strife-torn Mali.

Mr. Trudeau, famed for selfies, doesn’t share the fondness of Stephen Harper, his Conservative predecessor, for formal photo opportunities with Canadian troops. But Professor Sloan said that his government had not followed the mold set by many Liberal governments, particularly the ones led by his father, Pierre Elliott Trudeau, and then Jean Chrétien, of cutting back military spending. She also credits the current government for laying out a detailed, long-term plan for Canada’s armed forces, something Mr. Harper never offered.

Many of the programs and expenditures for that plan are way down the road. With no obvious, direct military threat facing Canada, Professor Sloan said she did not believe that Canadians would back a significant increase in the armed forces’ budget today. But as climate change continues to thaw out the Arctic, opening its passageways to foreign ships and creating the potential for conflict, she said that might change.

“As we become less geographically isolated, only then will our interest in military spending increase,” she told me.