Fun dark pattern on site : declining consent for tracking causes consent dialog to reappear infinitely on scroll. On top of a gdpr article. Oh the irony.
International law etc goes totally out of the window in a crisis like this. Look at Austria shutting the border to Italy, technically contravening the Schengen Agreement.
The Schengen Agreement allows for temporary border controls in certain circumstances. That's why (for better or worse) several EU states were permitted to set up temporary border controls in response to the migrant crisis a few years ago.