If the fight against the Covid-19 virus is like war, it looks like every commander-in-chief in every war room has a different strategy.

How come?

The enemy is the same, and every country has had about 18 months of the same experience fighting it.

Yet their battle plans differ so much.

How different?

The Australian city of Sydney locked down parts of the city in June after several cases of the Delta variant were detected, and has since extended it, possibly to the end of next month.

Melbourne and Brisbane have taken a similar approach, despite the fact that Australia has had relatively few cases - slightly over 40,000, including 975 deaths.

Its approach has been one of the most hawkish in the world - at one time even preventing its own citizens abroad from returning home.

The United Kingdom, on the other hand, looks like it is fighting a very different battle.

For more than a month starting in June, I watched on live television, along with millions round the world, four great sporting events taking place there: Wembley-based games from Euro 2020, the four-yearly football competition among the best nations in Europe; Wimbledon tennis; the British Open, an annual major golf event; and the Formula One race at Silverstone.

The sporting action was world class and the competition breathtaking at times.

But most remarkable for me were the huge crowds in the stadiums, on the golf course and the racing track. Tens of thousands enjoying their new-found unmasked freedom, cheering their teams and favourites on.

During this month-long sporting fest, the UK's daily infection numbers climbed to over 30,000 cases. But the Government stuck to its plans to lift almost all restrictions and opened up the economy.

Even larger crowds of up to 70,000 are now filling stadiums at Premier League football games, which kicked off this month.

Borders have opened in much of Europe, and life is returning to near normal in most countries there.

Japan's approach is another story altogether, and watching the Olympics, you have to admire the country's resolve to hold the Games without spectators but with its trademark fuss-free efficiency.

As expected, there was no shortage of sporting drama. But it was, above all, a much-needed gift to lift the spirits of a pandemic-weary world watching from afar.

All this while infection numbers were climbing in the country and daily cases now exceed 25,000.

Japan deserves a gold medal for braving the pandemic to hold this global extravaganza.

Is there an objective way to assess these different approaches and arrive at a consensus on which is the most effective?

After more than 18 months, with all the data available, surely the answer should be clear.

The results

If the objective is to save the most lives and keep the number of deaths down, there is little doubt which places did best: Those that imposed strict lockdowns or had strong lines of defences including testing, contact tracing and vaccinating.

China, New Zealand, Australia, Singapore, Taiwan, South Korea and Vietnam all recorded fewer than 100 deaths per million.

Countries that had a relatively relaxed approach to controlling the virus but tightened measures when the infection numbers increased, which was how much of Europe, including the UK, did it, saw much larger numbers of deaths - from 500 to 2,000 per million population.

The wide range reflects how proactive the countries were in responding to each wave, with Germany and the Netherlands at the lower end (1,000) and the UK and France with higher numbers (1,700 to 2,000).

Finally there were countries that tried to minimise disruptions to their economic and social life with minimum restrictions to movement and other activities such as Sweden, the United States and Brazil. It is interesting to note that the death rates in Sweden and the US were not much different from the top range of the second group, but Brazil's numbers are off the chart at more than 2,600 deaths per million population.

But what if the objective is not just the preservation of life but also of the economy?

This was the thinking of most European countries and the US.

You would expect that they would not suffer as much economically.

In fact, the data showed otherwise.

Some of the places with the strictest lockdowns actually experienced positive growth last year: Taiwan (3.1 per cent), Vietnam (2.9 per cent), China (2.3 per cent), New Zealand 1 per cent)

For the others in this group, the numbers were: South Korea (minus 1 per cent), Australia (minus 0.3 per cent), Singapore (minus 5.4 per cent).

Economic growth for the second group last year: the Netherlands (minus 3.87 per cent), Germany (minus 4.9 per cent), France (minus 8.1 per cent), UK (minus 9.8 per cent).

The third group which chose not to have too many restrictions: Sweden (minus 2.8 per cent), the US (minus 3.5 per cent), Brazil (minus 4.1 per cent).

One note of caution when interpreting the data: Each country's economy is different from another and growth is affected not just by public health restrictions but also depends on the structure of the economy, its reliance on external factors and so on.

But even accounting for this, it is surprising that the countries with the most severe measures did not experience the greatest economic decline, contrary to earlier fears.

Even in Australia and New Zealand, the economic fallout was far less than that in the UK and France.

It is therefore not true that a country that goes all out to save human lives will necessarily pay the highest economic cost.

The above analysis applies to the pandemic world before vaccines became widely available and were seen as the weapon of choice for most countries.

Now, with many, including Singapore, vaccinating the majority of their people, the issue has turned into how to progressively open up the economy while still doing enough to keep breakthrough infections down.

As this phase unfolds, the lessons learnt from the pre-vaccine pandemic period are still useful in the post-vaccine world.

I can think of three lessons.