The model divides investment into two areas: the classic or hard one, which would require a disbursement of three and a half points, and a second, softer one that would cover areas related to security.

NATO allies have started cobbling together an agreement to significantly boost defense spending in a way that may assuage US President Donald Trump’s demand to spend 5% of economic output on the military.

Trump’s demand has rattled many European allies, particularly those already struggling to meet Nato’s existing target of spending at least two per cent of GDP on defence. None of Nato’s 32 members, including the United States,