What Western countries should be doing to control the COVID-19 outbreak

China is almost the only country that has successfully controlled the COVID-19 outbreak (and, to a lesser extent, South Korea). Granted, they had a significant head start on everyone else. But we should still listen very carefully to what George Gao has to say.
Dr. Gao is the director-general of the Chinese Center for Disease Control and Prevention, and the point man for the remarkably sucessful Chinese response to the COVID-19 outbreak in China.
When asked what should Western countries do to better deal with the pandemic, he says that the biggest single mistake that North American and European countries are making is that people are not wearing masks. According to Dr. Gao:

"This virus is transmitted by droplets and close contact. Droplets play a very important role—you’ve got to wear a mask, because when you speak, there are always droplets coming out of your mouth. Many people have asymptomatic or presymptomatic infections. If they are wearing face masks, it can prevent droplets that carry the virus from escaping and infecting others."

Well, that sounds pretty clear. For what it's worth, I remember questioning the current wisdom that masks are useless way back on March 4th. There is a cultural barrier to overcome - Asians, wherever they live, seem to have no problem walking around wearing a mask, the average caucasian would be either embarrassed by, or downright resistant to, the idea. One Korean-Canadian explains how he felt perfectly comfortable wearing a mask in Seoul, but self-conscious to the point of non-compliance when in Vancouver. In South Korea, he would feel like a freak not wearing a mask; in Canada, he feels like a freak for wearing one.
The other important thing that Dr. Gao mentions that Western countries are not doing is the aggressive use of thermometers at the entrance to all stores, buildings, transportation stations, etc (and making sure that anyone with a fever does not enter).
And finally, people who tested positive but had only mild symptoms, were not just sent home, but were quarantined in large central facilities and not even allowed visits from family.
These are reasonably simple, common-sense measures that we could have (and probably should have) been employing for weeks now. They may be quite intrusive measures and many people may not like them, but I think we are probably past those kinds of considerations now. What we need is something that works.