"I can't tell you Aussies and Kiwis apart," I once confessed to a New Zealander.

I'm pretty sure I insulted him.

"There are huge differences, mate," the Kiwi corrected, "just as there are big differences between Americans and Canadians. If I said you lot were alike, you'd be offended."

Obviously, he took exception to being mistaken for an Aussie.

Ask a Hungarian in Budapest to pull a Canadian from a crowd of Americans and he wouldn't be able to do it. The rest of the world sees us as Siamese twins, but we know our differences. My Kiwi friend's comments speak volumes about personal and geopolitics Down Under — and in North America.

Americans and Canadians are different and proud of it, but we get along for the most part. The longest undefended border in the world — 3,987 miles — once sat between us. It's been militarized since the 9/11 attacks.

"When I have been in Canada, I have never heard a Canadian refer to an American as a 'foreigner.' He's just an 'American.'" Franklin D. Roosevelt once said. "And in the same way in the United States, Canadians are not 'foreigners.' They are 'Canadians.' That simple distinction illustrates to me better than anything else the relationship between our two countries."

I've visited British Columbia a dozen times. Six weeks ago my wife, Hedy, and I made our second foray into eastern Canada, visiting Montreal, Quebec City, Nova Scotia, New Brunswick and Prince Edward Island.

O Canada, we love you! You're so different, yet so familiar to us Americans.

The people elect to spell things strangely up there, however, like "neighbour," "centre" and "favourite." And they play football with only three downs. Their national obsession is ice hockey (that's roller hockey on ice skates. How quaint!).

Still, we're more alike than not, eh? (Eh — a ubiquitous Canadian term meaning "don't you think?")

I recently finished reading a controversial new book by award-winning journalist Diane Francis. Francis, an American-born dual citizen, is stirring contentious debate on both sides of the border with her book: "Merger of the Century: Why Canada and America Should Become One Country."

To be honest, it's set off a firestorm.

The author says we're both melting-pot nations, but Canada is significantly more Anglo-Saxon than we are. Francis opines that the U.S. has a "decidedly Germanic sensibility." More than 50 million Americans claim German ancestry.

Another important distinction is that the U.S. gained its independence in 1776. Canadians achieved their own citizenship 171 years later, in 1947.

"If they merged," Francis argues, "Canada and the U.S. would become an energy and economic powerhouse, occupying more land than Russia or the continent of South America. Better yet, Canada is virtually empty, thus providing enormous development opportunities.

"The two … could easily become not only energy self-sufficient but major energy exporters to Asia and other regions. [They] …could better tackle environmental challenges together through science and … combined … would have a larger economy than the European Union or than the economies of Japan, China, Germany and France combined.

"The merged nations would control more oil, water, arable land and resources than any other and would enjoy the protection of America's military. They would … eliminate trade and even government budget deficits, and would share a strengthened currency.

"A merger would … create the world's foremost business, creative, energy and mining superpower."

Strong arguments all.

Canada has — by far — the longest coastline in the world, 151,500 (mostly undefended) miles, and a navy consisting of just 33 ships and 8,500 regular personnel. Without a merger, Canada, which is vulnerable to Chinese and Russian Arctic poaching, "could," she writes, "become a resource battleground." The U.S. has a navy of 287 ships and 426,000 active and reserve personnel.

Francis argues that Republicans would like the merger for national security and capitalism reasons, and Democrats for the 35 million liberal-leaning Canadians who'd join the voter rolls. No Republican would likely occupy the White House again.

Francis sums up her case by saying: "The combination [U.S. and Canada] would be unbeatable."

Oh, and just so you know, there's a movement afoot in the Southern Hemisphere to unite Australia and New Zealand. No foolin' mate!

JIM CARNETT lives in Costa Mesa. His column runs Wednesdays.