By Nick Assinder
Political correspondent, BBC News website
Tony Blair is doing his best to keep the focus of the G8 summit on the so-called "legacy issues" he had hoped would help send him on his way out of Downing Street surrounded by a positive glow.
But in the run-up to the summit the continuing rift between Russia and the west continues to overshadow the big agenda items of climate change and Africa.
Mr Putin's nuclear threat may overshadow summit
And there remains real doubt over the chances of the meeting ending with a new agreement from the US on emission targets - although Mr Blair insists the key is getting a process going, with the US on board.
The prime minister undoubtedly wanted to be pictured as the leader who, above others, persuaded President Bush to get on board a post-Kyoto deal in time for an agreement in Germany.
But the president appeared to pull the rug out from underneath that one with his positive new tone in favour of international deals on the reduction of emissions, while also suggesting the big decisions could be postponed.
His apparent conversion was widely seen as a way of muddying the water and falling far short of what Mr Blair wants.
Mr Blair, however, continues to insist he can get a deal from President Bush on a process, already started by the president's remarks, and which will keep momentum going in the right direction. It may sound like a second best, but the prime minister sees it as a significant shift in the right direction.
There is still the danger, however, that the credit for any deal will fall to German Chancellor, and G8 host, Angela Merkel.
She will use a pre-summit lunch with the president to press him to go further on the issue of emissions and allow a genuinely radical communique to be signed at the end of the meeting.
Mr Blair wants to see breakthrough on climate change
But it is Russia and the talk of a possibly new cold war that is casting a dark shadow over proceedings.
On the eve of the meeting, the prime minister confirmed he was planning a "frank" conversation with President Vladimir Putin - diplomatic speak for a blazing row - over both his "new cold war" rhetoric and the extradition of the alleged killer of Alexander Litvinenko.
Mr Putin has branded the extradition request "pure foolishness" and shows no sign of being ready to climb down.
Mr Blair has said it is unacceptable to have someone murdered on British soil in that way and nothing happen.
He will also raise concerns over the president's threat to re-target Russia's nuclear missiles on Europe if the US goes ahead with plans to base a missile defence system in Poland and the Czech Republic.
Nothing to fear
It would not be in Russia's' interest to have a "scratchy" relationship with Europe and the west, he said.
Leaders are increasingly worried about the hardline tone coming from the Kremlin at a time when the US administration is domestically weaker than it has been, and as Mr Putin strengthens his grip in Moscow.
President Bush has kept the rhetoric going, telling Mr Putin there is nothing to fear from a missile defence system and even asking him to participate in it.
And the UK insists it is up to sovereign states like Poland and the Czech Republic to take their own decisions on the issue.
So it seems certain that, despite Mr Blair's best efforts, the event will be overshadowed by the growing rift with Russia.
With just three weeks to go until he finally hands over the reigns of power to Gordon Brown, Mr Blair may not get the G8 finale he had hoped for.