A Russian strike on a weapons factory in a European NATO country would trigger the alliance’s mutual defense clause, EU Defence Commissioner Andrius Kubilius told TVP World on Thursday. His comments came a day after Russian Foreign Ministry spokeswoman Maria Zakharova warned that European factories producing weapons for Ukraine were “potential military targets for Russia.” Her words raised concerns about the prospect of a direct confrontation between Moscow and NATO. Speaking to TVP World on the sidelines of a meeting of the European Parliament’s Security and Defence Committee in Brussels, Kubilius said: “I would say if Russia will hit our factories in European territory, that would be Article 5.” Article 5 treats an armed attack against one NATO member as an attack against all, requiring allies to come to the assistance of the country targeted. Putin issues nuclear warning over Kaliningrad Tensions along NATO’s eastern flank have risen amid suspected Russian-linked sabotage and cyberattacks across Europe, as well as a series of Russian missile and drone strikes close to the alliance’s borders. The incidents have fueled fears that the war in Ukraine could spill over into NATO territory. Russian President Vladimir Putin added to those concerns on Thursday by warning that Moscow could resort to its entire arsenal, including nuclear weapons, if Kaliningrad, Russia’s heavily militarized exclave bordering NATO members Poland and Lithuania, came under direct attack. “This is inevitable,” Putin said. No Western official has indicated there are any plans to attack Kaliningrad. Photo: Poland shares 210-kilometer land border with Russia's Kaliningrad region. Paulius Peleckis/Getty Images.