Could World War Three be started by an accident? An off-course missile hit a Polish village close to the Ukrainian border on Tuesday, sparking fears of global retaliation.

On a random night in 1962, most Western authorities sincerely thought that the world was facing imminent destruction.

Workers at a military base in Minnesota awoke to the worst case scenario: a nuclear alarm. Soviet pilots were hurtling across the ocean, nuclear bombs in tow.

Except, of course, they were not, or our lives today would look quite different. It was a false alarm. The culprit? A clumsy brown bear who set off the alarm by accident.¹

On Tuesday, we got a taste for how they must have felt in 1962. After months of nuclear threats by Russia's President Vladimir Putin, a Russian missile fell on a Polish village on the Ukrainian border, killing two people.

Poland is in Nato. The fifth article in Nato's joint treaty states that an armed attack against one country in the group (to which Poland belongs) "shall be considered an attack against them all".

In other words, attacking a Nato power is almost a sure way to trigger a third, and probably nuclear, World War.

Except that this, too, turned out to be a tragic accident. The missile is now thought to have been fired by the Ukrainian army in self-defence.

One wrong move can change the course of history. Some name this the "Franz Ferdinand effect" after an Archduke of Austria whose death led to World War One.

The Archduke was killed coincidentally after his driver took a turn onto the wrong street where an assassin happened to be walking by. His death caused 20 million more. And unhappy coincidences like this happen more often than you would think.

But some encourage us not to catastrophise. Nowadays we have structures in place to prevent absolute devastation.

Additionally, although Nato's treaty forces members to protect an attacked ally, they will most often respond with economic sanctions, not with military force. 

Yes: History throws up countless examples of accidents which almost caused nuclear wars. Eventually, we will stop getting lucky. We can control some of the variables, but at the end of the day the law of probability wins.

No: Nato proved with its careful examination of the facts in the Poland missile case that the time of accidental wars is over. Accidents will happen, but we are well-equipped to understand and deal with them.

Or... Perhaps not, but why should we take the risk? We need immediate better regulation of nuclear weapons, or better yet we need to find a way to get rid of them altogether.