The Trump administration’s pivot away from being the primary guarantor of European security has been a boon for the continent’s arms makers. Shares in the UK’s BAE Systems, Italy’s Leonardo, France’s Thales and Germany’s Rheinmetall are up between 63 per cent and 164 per cent so far this year.

Pentagon contractors based in the US, meanwhile, find themselves in no man’s land. Comments from a trio of industry bellwethers on Tuesday underscore the challenges.

In theory, manufacturers of fighter jets, battleships and missiles should be a defensive haven for investors, given that most build their products in America and sell primarily to the US government. President Donald Trump’s promise earlier this month of a record-breaking $1tn defence budget for next year should have provided a fillip for the sector.