How To Slash The Risks Of Nuclear War By 89%

Using an Abacus to count the risks of nuclear war.

Have you thought about nuclear war recently? Perhaps not, given the pandemic. But the danger hasn’t gone away. In fact, it’s never been higher.

So anything that will reduce the number of risks is welcome. Remarkably, the simple act of counting risks reveals how to slash their number by 89%.


After a nuclear war, we might never know the true cause. Chaos would reign. Tons of rubble would bury vital evidence.

But there would have to be a reason. A chain of events took place. A risk became a reality.

Those same risks live with us now. Like land mines in a field, they lie hidden and deadly.

Counting Risks

One way to reduce the risks of nuclear war is to cut the number of risks.

But first, we have to count them[1].

Nine countries in the world have nuclear weapons (nukes). But rather than dive in with all nine, we start with one country and build up.

One country

The USA became the first country to get nukes, in 1945.

One country means one risk:

  • USA

This risk became reality in August 1945. The USA deliberately nuked and destroyed Hiroshima and Nagasaki.

Two countries

Russia became the second country to get nukes, in 1949.

With two countries we have:

  • USA
  • Russia
  • USA—Russia
  • Russia—USA.

There are 2 single-country risks, and 2 double-country risks. That’s 4 in total.

The last two risks look the same, at first sight. But the difference lies in who fires first[2].

Three countries

The UK became the third country to get nukes, in 1952.

There are now:

  • 3 single-country risks,
  • 6 double-country risks, and
  • 6 triple-country risks[3].

That’s 15 risks in total.

Each risk has a different chance of happening. Triple-country risks are lower chance than double-country risks. It’s like dice – the chance of rolling three sixes is lower than the chance of rolling two sixes.

Four+ countries

Above four countries the risks skyrocket. Too many to count one by one.

So to reach our goal of nine countries with nukes, we need another approach. And a little maths and a pocket calculator comes to our rescue[4].

Here are the results:

Table 1 – Number of Risks of Nuclear War

Number of Countries with NukesNumber of Risks

So today we live with nearly a million unseen risks of nuclear war.

Today’s Risks

A million risks of nuclear war is a huge number. So how has the world managed to escape up till now?

Fortunately, many risks have a very low chance.

But add up a million low chances, and one of them might happen. Since 1950 there have been almost seventy close calls[5]. That’s about one every year.

In short, it looks like we’ve been lucky so far.

But that’s hardly reassuring, is it?

Horror of Nuclear War

Things only need to go wrong once.

Any nuclear war brings suffering and death on a scale never seen before. Hiroshima and Nagasaki were terrible, yes, but today’s nukes are many times more powerful. And there are many more of them.

Even a ‘small’ nuclear war, say between India and Pakistan, would mean:

  • Millions of tons of smoke block out the sun.
  • Temperatures drop due to lack of sun, ushering in Nuclear winter.
  • Global crops fail due to the freezing cold.
  • Two billion people face starvation.

Relying on luck is reckless when the future of the planet is at stake.

But since we have no choice but to play the game, it makes sense to increase the odds in our favour.

How To Reduce Risks

Hidden in Table 1 is an astonishing fact.

Instead of reading the table from the top, start at the bottom and move up. See how risks shrink going from nine countries to eight? A shrinkage of 89% to be exact.

Pie Chart showing how the risks reduce by 89% if one country disarms

Figure 1 – Effect of one country disarming

I find this astonishing! Because if just one country disarms, 89% of the risks must disappear. Like a magic trick, hundreds of thousands of risks vanish into thin air!

Campaigners for unilateral disarmament were right all along[6].

Unfortunately, although the number of risks shrinks by 89%, the total chance does not. That’s because the risks that vanish have a very small chance of happening[7].

Even so, the chance of nuclear war does reduce. And if one country disarms, others may follow.


A single country disarming goes a long way to reduce the risks of nuclear war.

But it’s not the whole answer, of course. As long as any country has nukes, risks remain. That’s why all countries need to sign the new Nuclear Weapon Ban Treaty and disarm.

Still, an 89% cut to the number of risks is a great result.

One worth campaigning for.


  1. Those events where at least one country, fires at least one nuke, that explodes in at least one city.
  2. Risks 3 and 4 have different chances and consequences. A decision to fire first is a political one, and the chance of so doing depends on the government. Consequences also vary depending on who fires first.
  3. The fifteen risks are: USA; Russia; UK; USA—Russia; Russia—USA; USA—UK; UK—USA; Russia—UK; UK—Russia; USA—Russia—UK; USA—UK—Russia; Russia—USA—UK; Russia—UK—USA; UK—USA—Russia; UK—Russia—USA. Each risk shows the nuke firing sequence. So USA—Russia means the USA fires first, then Russia fires. The targets and quantities of nukes launched can differ. For example, USA—UK—Russia could be because the USA and the UK fire at Russia, then Russia fires back at both. Or maybe the USA fires at the UK, then the UK retaliates, then Russia fires at the USA. The UK and the USA are close allies, of course, and are hardly likely to go to war. But it’s not impossible, it’s happened before (1775-83). Also, they might nuke each other by accident. The Sunday Times reported a training accident in 2016. The UK allegedly fired a nuclear missile that “veered off in the wrong direction towards America”. Happily, it was unarmed.
  4. The formula for the number of risks is ∑P(n,r), r: 1 to n; where P is the number of permutations of n objects taken r at a time, and n is the number of countries.
  5. Campaign for Nuclear Disarmament (2020) Security Not Trident. [online] Available at: <> (Accessed: 6th November 2020). See also: (a) Sarah Witmer (2017) Nuclear Close Calls. [online] Available at: <> (Accessed: 6th November 2020); (b) Future of Life Institute (2017) Accidental Nuclear War. [online] Available at: <> (Accessed: 6th November 2020); and (c) Wikipedia Contributors (2020). List Of Military Nuclear Accidents. [online] Available at: <> [Accessed 12 Nov. 2020].
  6. Unilateral disarmament means a country gets rid of its nukes without expecting others to do so.
  7. The risks that vanish are the nine-country risks – all the various permutations of nine countries. So although there are a lot of them (89%), the chance of any of them happening is low. We can get a rough idea of the risk reduction as follows. In the last 75 years, there have been two cities destroyed by nukes, and many close calls, especially the Cuban Missile Crisis. So let’s assume three events in the last 75 years – that’s a probability of 3/75 or 4% per year. The chance of at least one country going to war is (1-chance of no countries going to war). With nine countries this equates to (1-0.96^9 )=31%. With eight countries it’s (1-0.96^8)=28%. So going down from nine countries to eight countries would result in a 3% reduction in the total chance of nuclear war.

Get Free Email Updates!

Signup now and receive an email once I publish new content.

I will never give away, trade or sell your email address. You can unsubscribe at any time.

Powered by Optin Forms