Deep inside a decommissioned nuclear bunker built into a Cologne subway station at the height of the Cold War, tour guide Robert Schwienbacher says he is getting a number of inquiries from Germans asking for space available in an emergency.
Concerns of Germans that dissipated with the fall of the Berlin Wall are now creeping back after decades of peace. It is a flashback for a nation that found itself at the geographic and political center of the Cold War.
President Vladimir Putin has in recent months escalated his "special military operation" in Ukraine, calling up reservists and threatening to use nuclear weapons to defend Russian land, while U.S. President Joe Biden has talked of "Armageddon."