US intelligence discovered earlier this year that the Russian government planned to assassinate the chief executive of a powerful German arms manufacturer that has been producing artillery shells and military vehicles for Ukraine, according to five US and western officials familiar with the episode.

The plot was one of a series of Russian plans to assassinate defense industry executives across Europe who were supporting Ukraine’s war effort, these sources said. The plan to kill Armin Papperger, a white-haired goliath who has led the German manufacturing charge in support of Kyiv, was the most mature.