On the first day of an international climate conference in Moscow, President Vladimir Putin has said that Russia has not yet decided whether to ratify the Kyoto Protocol, the treaty aimed at curbing global warming.
Without Russia's ratification, the protocol cannot enter into force.
Even at the Kyoto Protocol's inception in 1997, there were indications that some nations saw it more as a trade opportunity than an environmental agreement.
Experts will not hazard a guess as to which way Putin will go
Last-minute revisions were made allowing rich countries to keep their own emissions high, instead paying poorer nations to reduce theirs.
The country which would end up paying most, it was thought, was the United States, while Russia would be the main beneficiary.
Up in smoke
In the protocol, greenhouse emissions are measured relative to a 1990 baseline.
Since 1990, emissions in most countries, industrialised and non-industrialised, have risen.
Former-Soviet bloc countries including Russia are the principal exception.
Their industrial output declined sharply in the years following 1990 and so did their greenhouse gas emissions.
According to some estimates, Russia's emissions will not get back to 1990 levels for at least 20 years.
So rich nations can buy "emissions credits" from Russia without any impact on Russia.
The treaty also allows countries to pay Russia to preserve its extensive forests and to plant new trees, which - though the science on this is uncertain - absorb carbon dioxide, the main greenhouse gas, from the atmosphere.
But now the US has withdrawn, and with it has gone Russia's main hope of making money from the treaty.
A year ago President Putin said he would ratify the Kyoto treaty but in recent days Russian officials have said they will not ratify without guarantees of income.
There is undoubtedly political pressure as well from both sides.
When Canada was wavering on ratification a year ago, the US lobbied hard for it to withdraw, and it is likely the Bush administration has been exerting similar pressure on Russia.
The Kyoto Protocol is the best chance of global pollution reduction
Whereas some politicians from the European Union - the bloc keenest on Kyoto - have said that if Russia wants to be Europe's ally on other issues it must ratify.
Two conditions have to be met for the Protocol to come into force.
First, it has to be ratified by at least 55 countries - which has already happened.
Second, it must be ratified by countries whose combined greenhouse gas production accounts for at least 55% of emissions from industrialised nations.
Since the US is the biggest emitter, its withdrawal two years ago meant that just about every other industrialised nation has to ratify.
Australia has also withdrawn, and Canada ratified late last year after intense and acrimonious debate.
Few would have predicted at the time of the Kyoto negotiations nearly seven years ago that governments would still be discussing its implementation.
It was only ever a first step to combating climate change.
It aims to reduce emissions from industrialised nations only by around 5%, whereas the consensus among climate scientists is that in order to avoid the worst consequences of global warming, emissions cuts in the order of 60% across the board are needed.
One of the big outstanding questions is how to involve developing nations in the negotiations.
Once Kyoto is ratified, discussions on that difficult issue could begin.
But as long as it is stalled, no further progress can be made.
And if the Kyoto treaty dies, it is difficult to see any immediate future for global measures on climate change.