Think back to the end of 2010. As always, there were lots of experts making predictions. About the stock market. The economy. Politics. War. How many of those experts said that within three months there would be a rebellion against the decades-old regime of Moammar Gadhafi, that Gadhafi would respond with criminal brutality, that the United Nations would authorize military force against Gadhafi's regime, and that fighter jets from Canada and other Western countries would be striking Libyan targets and enforcing a no-fly zone?

Answer: none.

Now imagine that someone had dreamed up that scenario and asked experts how likely it was to happen.

Answer: extremely unlikely.

And imagine that at the end of the 2010, someone had published the same fanciful scenario in this newspaper, and ordinary Canadians had been asked how likely it was that Canadian fighter jets would be flying missions over Libya a mere three months later.

Answer: Are you kidding?

Now, some may dispute my judgment. Yes, the unrest in the Middle East was a surprise. But the potential for unrest was well known. You might even say it was likely to explode. And if it did, you might have guessed it would spread to Libya. And if that happened, well, the chain of events leading to Canadian jets in Libyan skies is really not all that surprising.

Or so some may think. Now.

With respect, that's hindsight bias talking. As psychologists have shown in many clever experiments, our perceptions and memories change to match what actually happened. Thus, if we expect something to happen and it doesn't, we will remember ourselves thinking it was less likely than we actually thought it was. (Y2K? You weren't worried. Oh no.) And if a surprise happens, we'll think it was somewhat less surprising than it really was. (You had a hunch that Barack Obama would beat Hillary Clinton, didn't you? Sure you did.)

The simple truth is that the unrest in the Middle East was as unpredicted and unpredictable as the earthquake in Japan. And the suggestion that Canadian fighter jets might be called into action over Libya would have seemed bizarre only a few months ago.

Now, you might think this is all some sort of pointless intellectual game. It's not. It's actually crucial insight into a pressing political question. And much more.

The Conservative government says it will spend many billions of dollars buying a fleet of F-35 fighter jets to replace the aging CF-18s now flying over Libya. The exact cost is disputed and uncertain. But whatever it is, it's big. Should we do buy those jets? That's likely to be a major question in the next election.

To be clear, there are really two questions. The narrower one is whether the Conservatives' decision to forgo an open competition and buy F-35s makes sense, while the broader question is whether Canada should buy a new generation of fighter jets at all. I'm agnostic on the first, emphatic on the second.

The reason is not the supposed threat of Russian bombers that belong in a museum or any of the other silly arguments made by Defence Minister Peter MacKay. It's one that was expressed well by MacKay's parliamentary secretary, Laurie Hawn, last November. "Mr. Speaker, what we are very serious about is giving the Canadian men and women who carry out the very difficult missions on behalf of the people of Canada and others the very best equipment to do the job tomorrow and for the next 20, 30 and 40 years," Hawn said on the floor of the House of Commons. "We do not know what is coming in the next 20, 30 or 40 years and neither does the member opposite."

Not incidentally, Hawn is a former fighter pilot. Indeed, he was the first to qualify to fly the CF-18 solo. That was in 1982.

Remember 1982? It seems like another world. We were plunging deeper into the Cold War and fears of nuclear annihilation grew.

But then came Gorbachev and perestroika. The collapse of Soviet Communism. Tiananmen Square. The Gulf War. The decline of Japan, American resurgence, the tech bust, 9/11, Afghanistan, Iraq, the rise of China and India, surging commodity prices, the crash of 2008, global recession, and revolution in the Middle East.

Who foresaw any of that in 1982? Nobody. Who could have imagined the jets Laurie Hawn was flying that year would be carrying out missions over Libya in 2011? Nobody.

Last November, I wrote a column defending the purchase of new jets. "It is foolish to think we know with any precision what the military will have to do in the coming decades," I wrote, "and so operational flexibility is essential."

I expected to be proved right "in the coming decades." Instead, it took four months.

History is full of surprises.