How does Nato look at the age of 70? It's complicated

Squabbling, a spreading focus and Trump raise doubts about the effectiveness of the alliance

Seventy years after Nato was founded - to protect western Europe from Joseph Stalin's Soviet Union - the military alliance returned this week to its first home in London to discuss an increasingly sprawling set of goals while bickering leaders competed to see who could offer the most contentious soundbite.

Normally this is an arena that would be dominated by Donald Trump, although this time he was somewhat upstaged by Emmanuel Macron, whose pre-summit declaration that the organisation had become "brain dead" obliged Trump to describe his French counterpart's comments as "very, very nasty".