0 h 27 m, 27 nov 1958 año - USSR issued the 6 month Berlin Ultimatum

Descripción:

This was the demand of the withdrawal of forces from Berlin to make it a free and neutral city. This was to get the West to negotiate to the future of Germany and Berlin, or the USSR would sign a treaty with the GDR which would threaten the Western Powers.
This would cause the West to deal with and recognise the GDR which would make the Hallstein Doctrine irrelevent.