With the transatlantic alliance once again on the rocks, the question of how to guarantee Europe’s security without America has once again returned to the top of the agenda. One idea that gained prominence last year and has once again become a hot topic in Brussels is the concept of nuclear sharing. The thought that the two nuclear powers in Europe, namely France and the UK, might extend their nuclear deterrence to other European nations, thus replacing the long-standing nuclear umbrella of America over the continent.

So what is the concept of a nuclear umbrella? A nuclear umbrella is a type of security guarantee where one nuclear-armed state agrees to use its nuclear weapons to defend a non-nuclear country or countries from attack. Since the 1950s, most of Europe has been covered by the US’s nuclear umbrella, a large and sophisticated framework that includes intercontinental missiles, nuclear-armed submarines, strategic bombers, and an estimated 100 tactical nuclear bombs deployed at air bases in five European countries: Aviano and Ghedi in Italy, Büchel in Germany, Incirlik in Turkey, Kleine Brogel in Belgium, and Volkel in the Netherlands. 

However, the reliability of the US’s nuclear umbrella has been put into jeopardy by Trump’s isolationist foreign policy and general disdain towards NATO, as well as his overt threats towards other NATO members, including his repeated refusal to rule out using military force to annex Greenland, a semi-autonomous territory of fellow NATO member Denmark. In the words of NATO’s former deputy secretary general Rose Gottemoeller last week, “Everything the United States is doing to raise doubts about its support for the NATO alliance will raise doubts about its willingness to extend a nuclear deterrent guarantee to NATO Europe.”

If the US does actually withdraw or scale back its commitment to European security, particularly in nuclear deterrence, then France and the UK, the other two nuclear........

© Paradigm Shift