The United States has upgraded the B61 nuclear bombs in Germany, Der Spiegel reported on Friday.

This covert operation had taken place back in the fall of 2019. About 20 warheads were sent to the US for two days, where new software was installed on them.

For 48 hours, Germany was a nuclear-free zone that no one expected. German authorities had put the Bundeswehr on high alert if these weapons’ transport did do not go as planned.

And according to dpa, the German Air Force took part in secret exercises with NATO partners, which involved a scenario of starting a nuclear war. At that time, the Bundeswehr launched its Tornado fighter jets.