> The straightforward lesson to take from this is that international public health experts belong to a social and political class which thinks closing borders is bad for mostly domestic political reasons, and in the absence of external reality checks like a pandemic, people wanting to make a career public health can really only advance by mimicking the beliefs of the senior people who are the gatekeepers for advancement.

A statement like this just signals that the author has not been around many scientists in their life. The majority of scientists have a contrarian bias (they have to be, otherwise why would they search for new theories?). Also, being a scientist is not a very effective way to gain personal wealth or status, so people that stay in science beyond a PhD tend to have other priorities and life goals than most people with a similar breadth of options. I have worked at the Robert Koch Institute, the German equivalent for the CDC in the US, and know some of the people that have been advising the government. I can guarantee that being an advisor to the government was the career aspiration of absolutely none of them. However, their research is being funded whether or not there is a pandemic or an epidemic, so these positions grant them exceptional freedom in their pursuits. "Normal" scientists have to spend an extraordinary amount of time to secure funding for their research, much more than you would ever expect to spend advising a government during the rare crisis. So the incentive structure here is really quite straight forward and much less conformist or sinister than the article suggests.

The reality is that there are pretty straightforward reasons to believe that restricting border travel has a limited impact *unless* you can suppress travel basically altogether. The absolute key assumption here is that the border is porous and cannot be closed 100%. Clearly, this assumption is incorrect for Australia and New Zealand, which is why (I assume) experts there did argue for border closures (and why I was absolutely furious that the UK, my current home, did not do the same).

Specifically, in the wake of the swine flu epidemic, there was an influential computational paper that investigated the question "If you restrict border crossings at the onset of an (influenza) pandemic, i.e. before the disease becomes endemic in your own country, how long can you delay the peak given that you are still allowing some travel for export/import of essential goods?" The math in the paper was a bit more exact but a back of the envelope calculation can convey the key insight: Assume a simple susceptible-infected-recovered (SIR) model, where the increase in infected people is roughly exponential and the doubling time of the number of infected is -- for the sake of argument -- 1 week. If you restrict border traffic by 50%, you delay the peak of the pandemic by 1 week. If you reduce border traffic down to 25%, you delay the peak by 2 weeks, 12.5% -> 3 weeks, 6.25% -> 4 weeks, 3.125% -> 5 weeks, 1.5% -> 6 weeks.

So reducing your border traffic by approximately 99% buys you six additional weeks to prepare for the worst. However, in exchange, you have to source basically all materials for this preparation from within your borders, as well as support a somewhat normal life. Even if that were possible, the disruption to your supply chains might mean that the preparations might take much longer than normal, such that six additional weeks might not be sufficient under these circumstances either.

Now assume that it takes 3-4 months to reach peak pandemic once the disease has become endemic in your country. Do you suppress all border traffic for an additional 6 weeks?

Finally, consider that the doubling time for COVID was actually much shorter (at least initially, i.e. before lockdowns), namely 3 days and not a whole week (https://academic.oup.com/jid/article/222/10/1601/5879762). So instead of buying yourself 6 weeks, you are buying yourself 6 * 3 = 18 days. So instead of 3 months to peak, you would have gotten 3.5 months to peak. I am not an expert in logistics but I would assume that a complete disruption of global supply chains would have done more harm than the good that could have come by delaying the peak by 18 days.