Under my parapluie: Macron’s nuclear guarantee for Europe

In early March, at France’s nuclear submarine base in Brittany, Emmanuel Macron delivered perhaps the most significant speech on nuclear policy by any Western leader since the end of the cold war. After decades of flirting with the notion, a French president has finally made the move and offered their country’s nuclear umbrella to interested European allies. In view at last is that keystone of an autonomous European defence: an independent nuclear deterrent.

Nuclear deterrence is ultimately about confidence. An effective umbrella requires its beneficiaries to trust that their guarantor would be ready to run the appalling risks of resorting to nuclear use on their behalf. Equally, they need to believe the man in the Kremlin also sees the nuclear threat as sufficiently real to curb his appetite for risk-taking. That was the basis on which the US nuclear guarantee kept the peace in Europe throughout the cold war. Today, when no one can count on the US president for anything and the revanchist mission of his Russian counterpart is all too obvious, the question becomes whether France can offer an equally compelling guarantee.

There are two main aspects to this: the capacity, and the commitment, of the guarantor.

Capacity

Those relying on France’s nuclear guarantee need to be convinced its capabilities are up to the job. After all, what are a few hundred warheads against the thousands Russia has at its disposal?

During the cold war Britain and France, as “small” nuclear weapon states, came up with roughly the same answer—the doctrine of minimum deterrence. A nuclear arsenal, provided it was invulnerable to pre-emptive attack (that is, held on undetectable submarines in the depths of the ocean) need not be thousands strong. Indeed, it only has to be large enough to threaten a degree of damage to the aggressor that outweighs any gain he could possibly hope to make; adequate, say, to destroy Moscow and St Petersburg. No need to make the rubble bounce.

Both countries added one important doctrinal refinement: the concept of a single, final warning, nuclear strike before unleashing Armageddon. Macron reaffirmed this doctrine in his speech; France’s Rafale aircraft carry nuclear-tipped missiles designed for this mission. (The British abandoned their air-delivered nuclear bombs in the 1990s and reassigned the warning-shot job to their Trident submarines. The submarines were adapted to be able to launch a single missile with one small nuclear warhead—the size of the bomb the allies dropped on Hiroshima, so perhaps only one-tenth of the power of the rest of the warheads.)

Why provide for only a single “final warning” nuclear response? Because the idea of some ladder of nuclear escalation is absurd

The idea was, and remains, to counter any notions in the Kremlin that Russia could “escalate to deescalate”—seize a chunk of NATO territory and then freeze any alliance counterattack with one demonstrative nuclear explosion. But why provide for only a single “final warning” nuclear response? Because the idea of some ladder of nuclear escalation is absurd. Even “small” nuclear weapons are never “tactical”, as though intended for battlefield effect. As Ronald Reagan put it, “a nuclear war cannot be won and must never be fought.”

It looks as though China’s leader Xi Jinping has accepted this too: although he has offered Vladimir Putin “a no-limits partnership” as the Russian president wages his futile war on Ukraine, Xi has warned Putin against nuclear use. Of course, this has not prevented the Russians from nuclear sabre-rattling, unveiling new nuclear missiles and moving some closer to Europe (as with the forward-deployment of their dual-capable Oreshnik missiles in Belarus). Nor has it stopped them adopting a more aggressive nuclear doctrine, seemingly blurring the lines between conventional and nuclear warfare. But these are largely scare tactics.

And why not? Russia successfully manufactured a crisis within NATO in the 1970s and 1980s by forward-deploying their new SS-20 nuclear missiles, which panicked Europeans into demanding similar American missiles (cruise and Pershing). But it did not matter then, and it does not matter now, to a victim of a nuclear attack where the warhead was launched from or what carried it. However it was executed, such a strike would be a deranged risk. A single response in kind should be more than adequate to shock the aggressor back to reality before the horror of nuclear war is unleashed.

Commitment

Macron’s doctrine of nuclear use is persuasive, and France’s capacity to execute it carries conviction. But how to ensure adequate confidence in the French commitment to actually fire that warning shot when the crisis comes? After all, Macron’s speech made clear that France’s nuclear weapons will remain under exclusive French sovereign control (as both the Nuclear Non-proliferation Treaty and domestic politics demand).

This dilemma is hardly new. Throughout the cold war, the US was equally determined that allied fingers should not be allowed on the nuclear button (or indeed, allied feet on the nuclear brake). Western strategists devised the best available answer: the policy of nuclear “burden-sharing”. US free-fall nuclear bombs would be stored on European bases, for delivery by allies’ combat aircraft. Five European allies sustain these arrangements to this day. Before Trump, the degree of involvement with and insight into US nuclear planning afforded by these arrangements was a strong support for European confidence in the American guarantee.

Macron’s speech thus alluded to comparable plans to be developed with interested European allies. He spoke of forward deployment of Rafales and of joint exercises. He also mentioned allied support for French nuclear strike capability through such means as air defence and provision of satellite intelligence. Clearly, there will be much to discuss here. But Macron was able to name in his speech Belgium, Britain, Denmark, Germany, Greece, the Netherlands, Poland and Sweden as European allies with which France was already in discussion.

And the Brits

Where are the Brits in all this? Speculation about a “Eurodeterrent” has long envisaged it as something Britain and France should offer together. Today, as the government in London increasingly looks to reverse the damage done by Brexit, it has every incentive to fortify its European credentials by associating itself with Macron’s proposals. The old line of “our nuclear weapons are committed to NATO so of course cover European allies” is no longer adequate.

Long term, the Brits would do well to restore the air-launched leg of their sovereign nuclear capability. For now though, they should be conspicuously welcoming Macron’s initiative; offering it explicit doctrinal support; foregrounding their intention to further tighten bilateral nuclear cooperation with France; and, crucially, reversing the latest (unexplained, and inexplicable) decision to buy more American aircraft to drop more American bombs.

After all no one, least of all France’s allies, will miss the point that there could be a very different French president in the Elysée in 2027. France must do what it can to develop effective arrangements with its allies over the coming year. But a complementary guarantee from the UK, where no new general election is due until 2029, would be invaluable reinforcement. (Even NATO has long politely alluded to the added deterrent value of French and British nuclear forces, without of course implying any doubt about the US guarantee: “These Allies’ separate centres of decision-making contribute to deterrence by complicating the calculations of potential adversaries”).

The French deterrent should suffice to underpin the sovereign European defence that is now required: but two minimum European deterrents would clearly be better than one.