China successfully followed the same strategy, so the strategy certainly can work for large, non-island countries.
China had a few outbreaks (after Wuhan, obviously), but it responded to each one with quick restrictions on the affected location and mass testing of everyone in the region. That worked to contain these subsequent outbreaks.
As a result, China has been essentially CoVID-19-free for about a year now.
It's hard to tell what on earth is going on in China because a lot of the information coming out of there seems... dubious. As you say, they've had a few outbreaks which they responded to with large-scale lockdowns and mass testing, but if you believe their reporting the mass testing generally didn't find any cases at all which (if accurate) would mean the whole thing was for nothing. This seems unlikely. There were also weird WTF moments like in-hospital spread in a major city in a border region with a known outbreak going undetected for way too long at a time where even western countries that were "failing" at testing had enough in place to detect that. Also, a lot of the information about the source of the outbreaks and their successful methods for eradicating Covid is really obvious propaganda. On the other hand, their hospital system doesn't seem to be collapsing under a mass of Covid cases either.
It's not that difficult to know what's going on in China. There are many millions of Chinese people who call friends and family outside the country regularly. You can go read Chinese social media. There are Westerners in China who post to Western social media. There are even many people on HN who live in China.
> if you believe their reporting the mass testing generally didn't find any cases at all
That's not true. Their mass testing typically picked up further cases, which were isolated:
* In the June 2020 Beijing outbreak, mass testing uncovered over 300 cases.[1]
* In the October 2020 Qingdao outbreak, 9 additional cases (beyond the original three) were caught by mass testing.[2] That suggests that this outbreak was detected early.
* In the October 2020 outbreak in Kashgar, over a hundred additional cases were detected through mass testing.[3]
And of course, there was a more widespread outbreak in December (still concentrated in the Northeast), which peaked at over 100 new cases a day nationwide, and which was stopped with widespread lockdowns and mass testing.
> Also, a lot of the information about the source of the outbreaks and their successful methods for eradicating Covid is really obvious propaganda.
I assume you're talking about the cold chain. I don't see how that's "obvious propaganda." There's good evidence from contact-tracing that some of the subsequent outbreaks originated in people who work in the cold chain. It may seem strange from an American or European point of view, because the cold chain is way less of a problem than the literally millions of infected people walking around in Europe and the US. But in a country with essentially zero community spread and strict quarantine at the border, much less common pathways become a concern. It only takes one person touching a contaminated package and then touching their eyes to set off a new epidemic.
> There's good evidence from contact-tracing that some of the subsequent outbreaks originated in people who work in the cold chain.
Well, that's technically true. It just probably didn't come from the goods being handled like China claimed. In particular, formites and surface contamination of any kind don't seem to be a major source of transmission, and the Beijing outbreak they originally used this to explain seems to actually trace back to infected truckers travelling from somewhere in China with a previously-undetected outbreak that wasn't noticed before because locations outside Beijing didn't have the same level of testing. That is, they found it within their cold chain because that was where they were looking. This is also a lot more consistent with what we know about how Covid is transmitted.
> formites and surface contamination of any kind don't seem to be a major source of transmission
When there are millions of infected people walking around breathing and coughing, then fomite transmission is not a major source of transmission. But it is a source of transmission, and it could become the dominant source of new introductions of the virus into the country if quarantine of travelers is good enough (to go to China, you generally have to get a negative PCR test before your flight, then quarantine for two weeks in a special hotel on arrival, and finally get another negative PCR test). That's not to say that cold chain was actually the source of the Beijing or the Qingdao outbreaks, but there's evidence that points in that direction. In other words, this isn't simply propaganda.
But the larger issue that we were originally discussing is the overall situation in China. There clearly has not been significant community transmission over the past year, showing that the strategy (sharp lockdowns followed by strict border quarantines and mass testing during localized outbreaks) has been effective.
China had a few outbreaks (after Wuhan, obviously), but it responded to each one with quick restrictions on the affected location and mass testing of everyone in the region. That worked to contain these subsequent outbreaks.
As a result, China has been essentially CoVID-19-free for about a year now.