At these big diplomatic moments people pour over the theatre and the choreography.

The body language will be studied in minute detail. How long is the handshake? What do their faces say? Who looks more eager?

We know already that they are not scheduled to hold a joint news conference after their meeting, but will instead hold their own individual ones. Will they be simultaneous? And if not, who goes first?

Risk and reward

Behind all that though, there is serious risk and reward for both sides.

President Joe Biden has already been accused of having this meeting too soon, the suggestion being that he is somehow rewarding President Vladimir Putin, a man he called "a killer" not that long ago.

Yet, Mr Biden insists that every one of the leaders of the NATO member nations, with whom he met on Monday, supported the summit.

Dimitri Trenin, director of the Carnegie Moscow Center, told me: "This meeting gives a fraction of a chance to stabilise consultation, not to dilute it down or end it but to make sure people do not cross red lines on either side. In the very few issues they feel a need for cooperation they do so without impediment."

Red lines

"There are areas where we can cooperate if he chooses. If he chooses not to cooperate, then we will respond. We will respond in kind," Mr Biden warned at the NATO meeting in Brussels.

The American president has already said the Geneva summit will be about setting out "red lines" - a predictable but risky strategy.

If you set a red line you need have a penalty and be prepared to carry it through, if and when it is crossed. Barack Obama found that out with Syria - he set red lines on chemical weapons use. The line was crossed and he did nothing.

But from a Russian perspective the red lines here are thicker and the consequences of crossing them far greater.

Ukraine is key. For Moscow, the prospect of Ukraine joining NATO is a hard line not to be crossed as is the prospect of a US or NATO military presence in Ukraine. The buffer the country creates between Russia and the West is fundamental to President Putin.

"If Ukraine is offered action plan to join NATO there will be war and I mean war," Mr Trenin told me. "If there is an attack on Russia in Crimea there is also likely to be a major conflict..."

Central to these summits is an attempt by both sides not to lose face. There should be no expectation of acknowledgement by Russia of its alleged meddling in the US democratic process or cyber activity. But dialogue on these issues from a fresh starting point might be acceptable and would be a positive outcome.

Resetting the relationship

It's three years since the last US-Russian presidential meeting. Then-president Donald Trump met Mr Putin in Helsinki. The focus and the controversy then was Mr Trump's decision to take Mr Putin's word over his own intelligence agencies on the issue of election meddling.

Despite that, diplomatically the meeting was seen as being counter-productive for the relationship. The key this time will be to try to stabilise the strategic relationship between the two superpowers.

Alexei Navalny

Issues like Alexei Navalny, the Russian opposition leader, poisoned then imprisoned in Russia, are important for Mr Biden. It's a key subject which Mr Biden can use to show that he's being tough on Mr Putin.

"Navalny's death would be another indication that Russia has little or no intention of abiding by basic or fundamental human rights," Mr Biden said this week.

But he shouldn't expect any breakthrough or even much of a response from Mr Putin who will shrug and say it is a domestic Russian issue.

An echo of history

It was in this same city that Ronald Reagan and Mikhail Gorbachev held an historic summit back in 1985. The theatrical moments included a much-studied seven second handshake.

The meeting, complete with images of a cosy fire-side chat, prepared the ground for the thawing of relations between Russia and America. No one should expect the same this time.

Controlling the event to prevent any negative and potentially destructive moments is paramount and hard too given that diplomatic relations between the two countries are poor at the moment. Time to prepare for the meeting has been short.

A joint news conference was, it seems, just too risky for both sides. Domestically, Mr Biden is facing pressure from both sides, politically, over this meeting. He needs to go back to Washington DC demonstrating he has been tough. That would have required a win at a joint news conference which Mr Putin would never have tolerated.

So what would be seen as a positive outcome?

"A serious conversation..." Mr Trenin says. "As little theatrics as possible. An outward show of respect.

"A decision to go ahead with talks about talks on strategic stability. Maybe a couple of small things - the return of ambassadors. It means nothing but could be seen as a reset of the relationship."