The Next Proliferation Wave: Can Europe Go Nuclear?

An analysis of Europe's nuclear-related landscape shows that while proliferation on the European continent is possible, it faces severe obstacles.

Throughout the war in Ukraine, U.S. and Western decision-makers have repeatedly backed down in the face of Russian nuclear threats, undermining Ukraine’s ability to defend itself effectivley. Therefore, a key lesson states may learn from this war is that they need to build their own nuclear arsenals to protect themselves from conventional aggression by a revisionist nuclear power.

These considerations appear especially relevant to states bordering Russia, such as the Baltic states, Poland, Finland, and Romania, as well as countries located in the Indo-Pacific region that might fear China could replicate the Russian model, if Russia is not defeated in Ukraine and adequately punished for its transgressions.

This post is the first part of a two part series, focusing on the potential nuclear proliferators in Europe. Part two will focus on Asia.

Proliferation is risky business

Before looking at potential nuclear proliferation on the European continent, it’s important to get some basics out of the way. What obstacles are in the way of aspiring nuclear weapon states to fielding a credible nuclear deterrent?

First, proloferation is challenging. States must acquire the necessary fissile material to create a nuclear device, integrate this device into a functioning warhead, pair the warhead with a delivery system, create survivable basing modes for their nuclear weapon systems, and establish reliable and redundant command-and-control structures, among other challenges. In other words, getting your hands on the necessary uranium or plutonium is just the first step in becoming a veritable nuclear power.

Second, proliferation is expensive. There are various direct costs involved in becoming a nuclear power, such as building the necessary industry and acquiring the weapon systems. Additionally, significant economic costs may arise from potential sanctions imposed due to the proliferation attempt, which will likely be condemned internationally.

Third, proliferation is dangerous. States that are acquiring an independent nuclear capability are, on average, under significant duress in the years before and after proliferation, experiencing systematically more military conflict than non-proliferators. Vipin Narang, a professor at MIT, illustrates this with a neat graphic in his 2017 article, “Strategies of Nuclear Proliferation: How States Pursue the Bomb”.

Fourth, proliferation is very difficult to keep secret. All civilian nuclear programs are under the oversight of the International Atomic Energy Agency (IAEA) which applies safeguards to ensure they are not diverted for military use. While it is possible to shut out the IAEA, doing so essentially signals to the world that you are attempting to acquire a nuclear weapon, significantly increasing the risk of sanctions or attack.

If states conclude that acquiring an independent nuclear deterrent is still worth it, they must first overcome the technical obstacles involved.

Proliferation basics

The first challenge is acquiring the necessary fissile material. Proliferators can choose between two routes: a uranium and a plutonium route.

The uranium route requires enriching uranium-235 (U-235), the fissile isotope found in only about 0.7% of natural uranium, to about 90% for weapons use. This is done through enrichment technologies, which separate U-235 from the more abundant uranium-238 (U-238). Today, enrichment occurs exclusively (as far as I am aware) via gas centrifuge technology, though historically other methods have been devised and used.

The plutonium route involves using a nuclear reactor to irradiate U-238, which absorbs neutrons and transforms into plutonium-239 (Pu-239). After sufficient buildup, the spent reactor fuel is chemically reprocessed to extract Pu-239.

Both methods yield fissile material for a nuclear bomb. For example, China, India, and North Korea have chosen the plutonium route for their first nuclear device, while Pakistan and South Africa have pursued the uranium route. Iran is also primarily betting on the uranium route, while pursuing a plutonium route simultaneously.

Once the required fissile material is available, this material must be turned into a nuclear device that can create a super-critical chain reaction. This involves converting a subcritical mass of fissile material into a super-critical mass.

Today, the most common method to achieve this is to employ an implosion-type nuclear device, which uses conventional explosives arranged symmetrically around a core of fissile material (either plutonium-239 or uranium-235). Upon detonation, it compresses the material into a supercritical state, initiating a nuclear chain reaction.

The minimum amount of fissile material needed to create an effective implosion-type nuclear device is generally around 4-8 kilograms of Pu-239 or 15-25 kilograms of highly enriched uranium (though the exact amount depends on a range of factors).

The concept behind implosion-type devices is straightforward but technologically complex. It requires precise engineering of high-explosive charges to symmetrically compress a fissile core into a supercritical state. This could be one area where Iran is receiving aid from Russia in exchange for missile technology. New proliferators would almost certainly choose this design as well.

How easy would it be for European states to acquire an independent nuclear weapons capability?

Europe’s proliferation landscape

From a proliferation perspective, the "ideal proliferator" would have its own uranium enrichment facilities to produce highly enriched uranium (90% U-235). Additionally, it would possess heavy-water or graphite-moderated reactors, that can use natural or low-enriched uranium to generate significant amounts of Pu-239 (via a spent fuel reprocessing facility). The country might also utilize research reactors to produce additional small quantities of fissile material under the pretext of isotope production for medical or industrial purposes.

Let’s compare this “ideal proliferator” environment to the state of civilian nuclear energy programs in European non-nuclear weapon states.

The Netherlands hosts a major uranium enrichment facility operated by URENCO in Almelo. URENCO is part of a multinational consortium (with the UK and Germany) that enriches uranium for civilian nuclear fuel using gas centrifuge technology. This facility is only producing low-enriched Uranium, but could theoretically be diverted to produce highly enriched uranium.

In terms of reactors, only Romania operates heavy-water reactors at the Cernavodă Nuclear Power Plant which use natural uranium to produce energy and could theoretically produce a substantial amount of weapons-grade Pu-239 (perhaps as much as 280-420 kg per year), if the spent fuel is reprocessed correctly. However, for obvious reasons, this nuclear power plant as well as the URENCO facility in the Netherlands are under strict IAEA safeguards.

Finland, Sweden, Spain, Czech Republic, Hungary, Belgium, and the Netherlands, among others, use light-water reactors as part of their nuclear energy programs. While these reactors do produce some plutonium as a byproduct, the plutonium is typically less suitable for weapons use (more Pu-240 is created, requiring more extensive reprocessing), and the plutonium production process is much less efficient.

Several European countries, including the Netherlands, Germany, Poland, Sweden, and Belgium, also have research reactors. These reactors are employed for neutron and material research, and for producing medical isotopes. For instance, the High Flux Reactor in Petten, Netherlands, once supplied 60% of Europe's medical isotopes. When it faced bankruptcy, it jeopardized the global supply of these vital isotopes.

Some research reactors, like the FRM II Reactor in Garching, Germany, or the BR-2 Reactor in Mol, Belgium, use highly-enriched uranium. This supply could theoretically be diverted for a nuclear weapons program, but the low quantities involved and IAEA safeguards make this virtually a non-starter. Additionally, some reactors produce small amounts of plutonium; however, the minimal quantities make it a challenging endeavor. Many European research reactors using highly enriched uranium, like the two mentioned above, are currently also in the process of switching to a process based around low-enriched uranium.

Given Europe's advanced industries, several states could potentially develop implosion devices given some time. Additionally, missile-producing non-nuclear weapon states like Germany, Sweden, Italy, and Norway might quickly launch crash programs to deploy missile delivery systems within a short timeframe (either based on existing or new designs). States lacking existing missile industries like Poland, Romania, or Finland, for example, would face greater challenges, at least if they are not cooperating with other states.

In terms of basing mode, existing European submarine designs could likely be adapted, or mobile launchers could be developed. Airborne delivery based on stand-off or direct attack munitions using European fighter aircraft is also an option. Developing nuclear missile silos would make little sense due to lack of survivability.

The primary bottleneck for Europe is fissile material production. Other technical challenges could more easily be easily addressed with enough determination and political will.

How could European states go nuclear?

Currently, no non-nuclear weapon state has the capability to develop nuclear weapons independently and secretly. Potential proliferation candidates, such as Poland, lack the necessary nuclear-related infrastructure (enrichment facilities and/or suitable reactors). Additionally, countries like Romania or the Netherlands would find it nearly impossible to produce and divert sufficient quantities of fissile material without alerting the IAEA and the international community.

If European states would want to go nuclear, this would likely have to be a largescale and focused European effort that would likely involve being upfront with the world. In other words, European states would tell the IAEA and UN member states that a dramatically altered security landscape has made the current nuclear balance in Europe untenable. While this is theoretically possible, this move would almost certainly lead to the global collapse of the non-proliferation regime based around the Non-Proliferation Treaty and the IAEA. If the IAEA is shut out from Europe, it will be shut out elsewhere, including in Asia and the Middle East.

Three other points are important to keep in mind:

First, unless European proliferators collaborate with European nuclear-armed states (France and the UK), this process would be relatively slow. Establishing the necessary infrastructure to supply and produce sufficient quantities of fissile materials would likely take considerable time. This is a major difference to potential Asian proliferators, like Japan and South Korea, which retain much higher levels of “nuclear latency” (the ability to quickly develop nuclear weapons, based on its existing technological infrastructure and knowledge, without having actually built or deployed them yet — further explored in the part on Asia).

Second, this process would most likely not have the support of the United States and could even provoke hostility. The United States has for a long time threatened South Korea with abandonment if it pursued an independent nuclear deterrent, and a similar stance would likely apply to Europe. While having more nuclear-armed states might enhance European security in the long term, active nuclear proliferation could severely undermine it in the short to medium term.

Third, there is a risk that Russia would preempt the acquisition of nuclear weapons by more European states, in particular those close to its border, by starting a conflict before they build up a survivable nuclear deterrent. This is especially likely after U.S. withdrawal.

In my view, there are scenarios where more European nuclear arsenals could be beneficial for the West’s collective security. However, it's crucial to remember that such a “proliferated” world would differ significantly from the one we live in today, and at least in the short term, it could be very dangerous.