[makomk]

Testing every single person arriving from abroad wouldn't work. The test is not reliable for people still in the incubation phase, and with exponential spread being what it is there are going to be a lot of those. I don't think there's any country on the planet taking that approach; they're all either banning travel from affected countries or forcing a 14-day quarantine period on travellers from them. The American media seems to have oversold people on how powerful testing is for domestic political reasons.

Also, 4 hour turnaround testing is really hard and I don't know of anywhere other than South Korea has managed it. They basically have to process the tests on site after collecting samples to achieve that, which is no easy feat as it requires not only specialised equipment and trained staff but also a carefully set up positive pressure room to prevent sample contamination. Plus, one of the key things that makes South Korea's approach so effective is that people drive up, get a sample taken, then immediately drive home to avoid spreading the disease to anyone else rather than waiting around for results.

I haven't even seen any examples of countries with substantial travel from Europe that routinely test people who've been there recently and developed mild potential symptoms. South Korea probably could but I haven't seen any confirmation that they do; they mostly seem to be focused on contact tracing and the large local outbreak. The UK and Europe don't. Maybe China does? Again, the American media has been running stories making it sound like the fact the US isn't testing everyone with a cough and a sniffle puts them massively behind the rest of the world and confusing people about what the rest of the world is actually doing.