BERLIN — European nations should develop a joint tactical nuclear deterrent to counter Russia’s expanding arsenal, Airbus board chair René Obermann said Wednesday, breaking one of Europe’s biggest defense taboos.

Speaking at the Berlin Security Conference, Obermann said Europe’s current posture leaves a dangerous gap below the strategic threshold, pointing to what he described as “500-plus tactical nuclear warheads” deployed by Russia along NATO’s eastern flank and in Belarus.

“What do you think would be our answer to a limited Russian tactical strike with limited effects?” he asked the audience of defense officials, military officers and industry executives. “I don’t have the answer — but I’m sure you do.”

Tactical nuclear weapons have smaller explosive yields, typically ranging from 1 to 50 kilotons, and are supposed to be used in battlefield situations. Larger strategic weapons have yields above 100 kt and are designed to flatten cities.

Obermann argued that Germany, France, the U.K. and “other willing European member states” should agree on a “common and staged nuclear deterrence program,” explicitly including the tactical level — a space traditionally avoided in public debate by European leaders.

France and the U.K. maintain independent nuclear arsenals, but there is no shared European doctrine on how to deter or respond to a limited nuclear strike. France is estimated to have about 290 warheads and the U.K. has about 225 warheads — none of them are tactical.

Germany participates in NATO’s nuclear-sharing mission but does not possess its own weapons.

Russia has about 5,580 nuclear weapons, the world’s largest arsenal.

Obermann warned that Europe risks misunderstanding Moscow’s strategy if it focuses only on high-end strategic forces while ignoring Russia’s large tactical stockpile. A credible response, he said, would send “a massive sign of deterrence.”

His call could stir debate across Europe’s capitals, where nuclear policy remains politically sensitive and largely siloed at the national level. It also highlights how Russia’s war in Ukraine — and Moscow’s repeated nuclear signaling — is forcing European officials and industry leaders to confront questions once considered politically untouchable.

The growing threat posed by Russia — German Defense Minister Boris Pistorius warned over the weekend that Moscow could attack a NATO member as soon as 2028 — and the worry that the U.S. under Donald Trump is no longer a reliant security partner is prompting European countries to take a hard look at nuclear options. Earlier this year, Poland said it will look at gaining access to nuclear weapons.

Obermann’s remarks come as European governments step up spending, modernize their militaries and navigate questions about long-term U.S. security guarantees.

CORRECTION: This article has been updated to reflect that neither France nor the U.K. have tactical nuclear weapons.