After four decades in the Senate, the majority as the USA's foreign policy man, and eight years as Vice President, again with foreign relations at the top of his list, Joe Biden knows the ways of global summits.
The back-slapping, the back-sliding, the back-stabbing. The big promises, big talk and bonhomie that lasts about as long as the summit itself.
In June, at G7, as he returned to the foreign policy fold this time as President many of his fellow world leaders felt relieved that with Biden they knew what they were getting.
For him it was an easy sell - I’m the new guy not the old one, the chaos and unpredictability of the Trump era is done, America is back. The old America, friend and ally, leader of the pack.
What a difference a few months and a different number after the G makes.
The President Biden of G20 doesn’t have the clean slate of the G7 days.
Here in Rome he has some nerves to steady. The debacle of the Afghanistan pullout is still too vivid, the whiff of "America First" is in the air. For all the smiles and handshakes many world leaders and those within their delegations are still stunned by the way the US conducted itself and how the consequences live on.
Then there is the issue of vaccine donation, not at a level many would like and far from all the promises.
For the French , despite the meetings of yesterday, the awkward AUKUS submarine row has left an lingering disquiet. It’s a disquiet shared by others.
It doesn’t help that he arrives in Rome a leader who hasn’t yet managed to rally his own troops around his flagship policies. Not great when you’re hoping to rally the world around policies that aren’t top priority for all.
On a personal level President Biden is good at these events, he has the easy way of a man who has spent a career making deals.
It is unfortunate that in the big job many are starting to worry he is more deal breaker than deal maker. In speeches over the decades he’s delivered the same line - that he’s good to his Biden word.
The world is hoping that is more than a good line and the deal maker of the past will emerge for the future.