The celebration of NATO's birthday began with Donald Trump branding his French counterpart Emmanuel Macron "nasty" and ended with the US president describing Canadian Prime Minister Justin Trudeau as "two-faced". It is a measure of Trump-era personality politics that NATO officials will be congratulating themselves on just how well it all went.
Broadly speaking, the summit will have been seen as a success by most of those behind it. The alliance – formed 70 years ago to confront the Soviet Union and now working out how to manage relations with Russia and China – avoided a major crisis.
The strain, though, was showing on all concerned – not least NATO Secretary-General Jens Stoltenberg, the man responsible for holding it all together. Widely seen as one of the canniest international operators, particularly when it comes to managing Trump, the former Norwegian prime minister gave a somewhat testy performance when interviewed by a BBC journalist as part of a parallel "NATO Engages" event. Having just sat stoically through Trump's unexpected Tuesday morning press conference, Stoltenberg was repeatedly asked about comments by Macron describing the alliance as "brain-dead".
"It would be strange if twenty-nine allies with different political parties, different history, different geography, always agreed on everything," Stoltenberg said. "But the lesson we have learned from history is that despite these differences we have always been able to unite around our core policy to protect and defend each other."
Far from being in crisis, Stoltenberg argued, NATO was as active as ever, with several battle groups of combat-ready troops deployed in the Baltic states and Poland – a consequence of European nerves following Russia's 2014 annexation of Crimea. Signing off new defence plans for those was one key aim of the summit – although that too at one stage looked in doubt, jeopardised by Turkish President Tayyip Erdogan, who threatened to veto them altogether.
Exactly how Erdogan was mollified remains unclear. But there was little official mention of recent spats between Turkey and the West over Syria and the purchase of a Russian S-400 air defence system. The latter has already prompted the suspension of Turkey from the US-led F-35 programme.
Stung by Western criticism of his operations in Syria, at one stage it looked as though Erdogan hoped to force more allies to add Kurdish militant groups, including former US allies, to terror lists. That never seemed likely to happen, but the question underscored one of several concerns being voiced around the edges of the conference – that issues of substance were too often being brushed under the carpet, given the need to manage the egos of Trump, Macron and Erdogan.
"What do you expect?" said one NATO official. "He is dealing with three particularly challenging presidents."
Outside that trio, most of the other big NATO players probably feel they got what they needed for their own domestic politics. For Boris Johnson, that meant avoiding getting too close to Trump. The prime minister avoided mentioning the US president at all by name in his final press conference. Trudeau got to needle Trump from the sidelines, and avoid any serious commitment to raising Canadian defence spending to the NATO target of two percent of GDP. Chancellor Angela Merkel appeared a much less central figure than she often does, with Germany again showing slippage in terms of its own military spending targets.
Trump, though, still came away with enough commitments of further spending to fuel his electoral rhetoric. Paradoxically, Macron's pre-conference criticisms of the alliance seemed to prompt Trump to jump to NATO's defence, something that will have brought many, not least NATO's Eastern European states, considerable relief.
For the Baltic states of Estonia, Latvia and Lithuania and others nearby, Russia remains the only existential threat they truly care about, but it is clear that even they are unsure exactly what that means. Five years after the annexation of Crimea and the beginning of Ukraine's long war, the prospect of direct Russian action against any NATO state is felt by many to be remote. But they remain nervous – and desperate for solid signs of US and NATO commitment that they will be defended if attacked.
For now, the presence of German, Canadian and British led battle groups in the Baltics and a US force in Poland provides that reassurance. The major US Defender 2020 exercise will see an even larger US force brought across the Atlantic to Europe.
Still, some analysts are nervous. A report last week from London's Royal United Services Institute think-tank raised concerns over the mismatch between NATO firepower in Eastern Europe and the overwhelming force Russia could deploy in any land-grab along its immediate borders. Such an assault, some analysts fear, could be over in a month, well before major US forces could cross the Atlantic to help repel it.
Few in London this week questioned that the US security guarantee will remain. But despite being organised by the US-based Atlantic Council, the "NATO engages" public event contained not a single speaker from the current US government. Before the Trump era, that would have been unthinkable.
The assumption, of course, is that a titanic confrontation is in no one's true interest, particularly in a nuclear era. Behind all the personality politics remains the still largely unquestioned belief that NATO states between them have the military, diplomatic and financial power to deter any foe from making such a move. We will have to hope that they are right.
A former reporter for Reuters, Peter Apps is a writer on international affairs, globalisation, conflict and other issues. He is the founder of the Project for Study of the 21st Century (PS21), a non-national, non-partisan, non-ideological think tank. Paralysed by a war-zone car smash in 2006, he also blogs about his disability and other topics.