Russia, watching on, teased that this was an anti-Trump gathering, skilfully picking away at the vulnerability of a divided West.

Sir Keir and others were insistent it was nothing of the sort. The prime minister was determined to be an honest broker between two allies, America and Ukraine.

What the summit felt like was Europe trying to prop back up the plan for peace in Ukraine, while recognising publicly again that the continent will need the US to be confident the war can end permanently.

Domestically - and this might seem parochial in the context of such a broad international picture - the prime minister is gathering a lot of support from many across politics for what he is trying to achieve.

Sir Keir and his still new-ish government has had a bumpy start in many ways, but he has seized this crisis and is shaping events, alongside others, and seems possessed of a determination and clarity of mind about what he hopes to pull off.

It is worth remembering two things right now: if a peace deal can be done, there are big implications for many families around the UK, including the deployment of soldiers and airmen and women to Ukraine - a volatile, contested place that Russia has had designs on for decades.

Their role would be peacekeepers, yes, but many would see them as being on the frontline of freedom.

There may right now be widespread political support for this, but that does not diminish the magnitude of what would be asked of those sent there.

The second thing to keep in mind is there is still a lot of diplomacy to come. We can expect plenty more days like the last few at home and abroad.

The path to peace could yet be long.