The U.S. seems to be on its way out of Europe. And this is not just the Trump administration’s doing. America has more pertinent issues at its doorstep, from a fiscal crisis to a menacing China. From this departure, Europeans have to figure out what to do and how to defend themselves. Some have written of the possibility of Europeans building up their own nuclear arsenals or for France and the United Kingdom to increase their nuclear capabilities to defend the rest of Europe. Having Europeans relying on nuclear weapons is appealing: it’s cheaper than non-nuclear capabilities—conventional weapons. It’s defense on the cheap. But Europeans should resist the siren calls for more nuclear weapons. More of them won’t protect Europe.

The most obvious case against increasing Europe’s nuclear capabilities is that Russia just has far too many, 4,400 warheads to be exact. This is leagues ahead of the combined 515 warheads that the United Kingdom and France have. It would be very difficult for Europe, specifically France and the United Kingdom, to match Russia’s amount. And if both aim to protect other European countries with nuclear weapons, they would have to match, if not out-match, Russia’s number of nuclear weapons to reassure its allies that they would come to their rescue.

There’s also the issue of nuclear weapons being limited in solving political problems. War and military capabilities are meant to have political goals, some tangible achievement. Nuclear weapons have selected political purposes for truly existential crises. For Europe, its political goals are to deter a Russian invasion of its eastern neighbors to prevent a fait accompli. It’s difficult to envision a scenario where the benefits of using nuclear weapons outweigh their costs. The European continent is small compared to Russia or North America, making the detonation of just one of these weapons horrific and costly for the entirety of Europe. And nuclear weapons have a slim chance in deterring a limited aims attack. The use of nuclear weapons here is overkill, and thus uncredible. It is hard to imagine Paris using nuclear weapons on behalf of Vilnius in Lithuania. At the end of the day, nuclear weapons aren’t credible enough for achieving Europe’s political goals.

Finally, there’s the underlying fact that relying more on nuclear weapons for defense makes it more likely for them to be used. Russia would have to be convinced that Europe would actually use nuclear weapons to defend parts of Eastern Europe from a Russian invasion. With a reliance on nuclear weapons, Europeans would be left with fewer military options for which to deter and potentially fight Russia. This would increase the chances for miscalculation and the preemptive use of nuclear weapons where, in an effort to show their metal, Europeans would feel compelled to launch nuclear weapons if they suspected Russia of launching an attack. Non-nuclear warfare is extremely destructive. The wars in Gaza and Ukraine have shown its ghastly effects. But nuclear war would be opening Pandora’s Box, and the results could be much, much ghastlier.

All this is not to argue that Europe should not have any nuclear weapons; it just needs to not put all its eggs in this basket. Instead, allied European countries should focus on improving conventional military capabilities. Returning to a point mentioned earlier, the political goal of Europe is to deter a Russian fait accompli in Eastern Europe. To do that, Europeans must make their military capabilities painful and credible to the Russians. Conventional military capabilities can accomplish this. Effects of building these up will be more expensive than nuclear weapons, but the efforts will be worth it if they decrease the chances of nuclear weapons being used and prevent Eastern Europe from being invaded.

Nuclear weapons are important for defense and deterrence. Yet, policies for how to use them can’t be applied in a cookie-cutter-like fashion for all countries and situations. Nor should countries discount non-nuclear options for deterrence. Both are important in their own ways, and the means to deploy them depend on a political case-by-case basis. By focusing on the improvement of its conventional military capabilities, Europeans can stand on their own two feet and stand steadfastly.