Quarantining incoming travelers from high-risk destinations will likely help, but will NOT achieve the same thing. COVID-19 is already here and circulating in the community. It has been for weeks. We just aren't testing for it (this will change in days or maybe a week, so wait for the big explosion in cases). Two weeks ago, there was capacity to administer and process 700 tests. Not 700 per day. 700 total. It has improved a little since then. But it is only now that actual significant testing capacity is being brought on board. Something S. Korea has had for about a month. We are way way behind.