Important: flattening the curve is *not enough*. No country has enough hospital capacity to deal with the massive surge of cases that will arise, even if it's slower. Japan is best prepared, and it has 13 hospital beds per 1000 people. The global average is about ~2 per 1000 people. Emergency care/ICU beds are ~20 times lower than that. And nobody has any pre-existing immunity to this virus, so everyone can get infected.
Instead of slowing the surge through relatively mild action, we ought to go very hard now to reverse it, as China and South Korea have done. This is presently being dismissed as an option because it is thought that this would have to last many months, and when you relax, you get the epidemic anyway. But this is not true - a few weeks of intense effort could buy us the time to 1) do much more testing and tracing, which lets us identify new cases early and prevent subsequent surges, 2) develop medication/vaccines, 3) build up medical capacity, and 4) learn much more than we presently know about it.
I am not an expert in this, so I would love to hear counter-arguments.