Former United States Defence Secretary Donald Rumsfeld famously observed that, “there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know.” While he was referring specifically to the American allegation that Iraq was harbouring “weapons of mass destruction” his comments could just as readily be applied to the current Covid 19 situation.

While most will be familiar with Covid19’s “known knowns” and the steps being taken by governments around the world to address those, the “known unknowns” and the “unknown unknowns” are a still a different situation altogether. Amongst the “known unknowns” two issues rank highly. The first relates to the way in which the virus is mutating, and the second the best way to move to a post Covid19 environment.

Already, the virus has been through many mutations, a few more virulent than others. The world is currently in the grip of a so-called Delta variant which appears to be more transmissible, cause more severe illness and potentially reduce the effectiveness of vaccines or treatments. What may come next and how potent that will be we do not know, but we do know, consistent with the nature of viruses, that Covid19 will continue to evolve. Nor do we know whether existing vaccines will prove up to the task of controlling all variants, or whether different formulations or combinations may be required. And we do not know what the level and impact of herd immunity will be, as and when it develops, and the extent to which it may vary from country to country.

The decision of countries like Britain and Singapore to move away from government-imposed restrictions towards a greater reliance on vaccination and personal responsibility to curb the spread of the virus is one most countries know instinctively they will have to make at some stage. None but the most rigid believe that humanity can survive indefinitely living in a set of disconnected hermit kingdoms. But what is not known is whether the steps being taken now by the likes of Britain and Singapore are precipitate and will cause even more problems than we currently face, or whether they are the way of the future. In the event it is the latter case, while we might accept that things will need to be different from what we knew before, we do not fully know what those adjustments will be, or how societies will react to their becoming the new normal.

As far as vaccination and testing are concerned we know these are likely to be critical elements of our futures. But will that mean annual vaccinations, like we have for the flu, and how readily will supplies of vaccine be maintained and supplied? What scope will there be countries to take advantage of some of the patent relaxations in place for existing vaccines to replicate or develop vaccines for their own countries, perhaps in concert with regional partners? And how will vaccinations be recognised across international borders?

At some point, international travel for other than essential purposes will resume, and people will expect relatively free movement across borders, although perhaps not to the extent previously. How will that work in practice, and what requirements will governments place on travel companies, airlines, shipping companies and tourism operators to ensure that public safety is maintained? Will they be practical and facilitate the return of international travel, or will they be so restrictive as to stifle it altogether?

Perhaps the biggest “known unknown” is the prospect of another virus, totally unrelated to Covid19, but no less virulent, while the current pandemic remains. Given the ravages Covid19 has already caused, and the international social and economic consequences of these so far, would the world cope with such a situation, or would it simply overwhelm many countries?

However, challenging as many of the “known unknowns’ are, and the uncertainties that still lie ahead in addressing them, they pale into insignificance alongside the “unknown unknowns—the ones we don't know we don't know” as Rumsfeld described them. By definition, our capacity to address these is severely limited because we do not know what they are or when they might arise. Therefore, applying the same solutions to them when they arise as we have to previous situations like the original Hong Kong flu, SARS and now Covid19 is unlikely to work, no matter how successful things were first time around.

What emerges from all this is a need for governments and their advisers to remain forever flexible in their policy responses to the twists and turns of Covid19, its variants and the other viruses that will assuredly come along. Their starting point must be to prevent the next epidemic becoming the next pandemic. In a world of constantly changing circumstances the need for governments to be ever nimble, open to new ideas and challenges to those ideas, and prepared to modify and adjust their approach as necessary is paramount.

There is still a long way to go on this journey. But there is one blunt and pervasive universal lesson, whether the crisis at hand be political, economic or social. Governments that assume they have all the answers and do not need to consider more diverse opinions to understand more widely what is going on around them, nor show any willingness to move from their original position, are most likely headed for failure.