We (the Czech Republic) and many neighboring countries did just that - the borders have been closed for everyone since middle of March, with police and army mak

We (the Czech Republic) and many neighboring countries did just that - the borders have been closed for everyone since middle of March, with police and army making sure this emergency meassure is observed. Only goods trains and trucks are let through and even they are often checked for compliance (driver has no fewer, etc.). Even cross border workers had to either stop commuting or arrange temporary accomodation on the other side of the border. So it is definitelly possible to "emullate an island" even in the middle of Europe, and it seems to have worked for the countriws that did it - daily case numbers are staying low, death toll is really low, so some of these restrictions are slowly being rolled back, with cross border bis and train lines resumming from 15th of May.