France warns Germany ‘you could reach the nuclear threshold without realising’ over missile threat to Russia

France has warned Germany that its expanding long-range missile programme could risk triggering a nuclear confrontation with Russia unless Berlin sets out clearly how the weapons would be used.

The warning exposes growing tensions among European allies as they race to strengthen their defences against Moscow while confronting the danger that conventional strikes could be mistaken for the opening moves of a wider war.

Germany is among several countries, including Britain and Poland, seeking to bolster its military capabilities to deter potential Russian aggression. Berlin is reportedly acquiring and developing ground-launched missiles with ranges of between 500km and more than 2,000km.

But French and German officials are preparing to discuss how the weapons should be deployed, amid fears that attacks on Russian territory could provoke a nuclear response, according to the Financial Times.

Army chief warns ‘the next battlefield is our economy’ as Russia is targeting Europe’s industrial strength

Navy chief sounds the alarm Britain must ‘prepare for war’ as the threats from Russia are multiplying

At the heart of the disagreement is the definition of “deep precision strikes” — conventional attacks against targets deep inside an adversary’s territory. French officials fear that without a shared understanding of their purpose and limits, Moscow could misinterpret an attack and escalate the conflict before European leaders realise the danger.

“If the Russians don’t get the signal right, you could get to the nuclear threshold without realising,” one French official told the newspaper.

The stakes are particularly high for France because of President Emmanuel Macron’s policy of “forward deterrence”, under which Paris is seeking to extend the strategic reach of its nuclear deterrent in support of European allies.

French officials fear that Russia could hold France responsible for strikes carried out by partner countries, potentially drawing Paris into a confrontation it had not intended to initiate.

“If you invite someone into your house, you are responsible if they set it ablaze,” one official familiar with the discussions said.

Six people familiar with the talks told the FT that France wants to align defence programmes and establish clearer rules governing the use of long-range weapons.

Germany is a particular focus because of the scale of its planned military expansion. Berlin is expected to spend €780bn on defence over the five years to 2030, giving it an increasingly prominent role in Europe’s security architecture.

“There are habits we developed over time. The Germans do not have it,” one source said, arguing that a clear and public doctrine would reduce the risk of Russian miscalculation.

A senior German official agreed that European capitals needed “a joint doctrine and a joint understanding about the escalation ladder”.

A British official, however, cautioned against underestimating how quickly Germany’s strategic outlook was changing, saying allies should embrace its growing military role rather than cling to old stereotypes.

The discussions come amid wider efforts to strengthen Europe’s nuclear deterrent. Earlier reports said Germany was in talks to help fund Britain’s Trident programme, underlining how the continent’s defence relationships are being reshaped by the threat from Russia.