Russia has asked for Britain's help in resolving the impasse in talks over the proposed European nuclear defence shield with a warning that retaliatory "military steps" will be taken if the US and Nato go ahead with the programme without the Kremlin's consent.
Moscow's disquiet over what it considers intransigence by Washington was conveyed by Dmitri Rogozin, the ambassador to Nato, during a visit to London last Friday.
Mr Rogozin will be visiting a number of Alliance member states to stress that ignoring Russia's position will have ramifications not just for European defence but on a wider field, including co-operation over Iran, Syria and Afghanistan.
The ambassador stressed that the US and, by proxy, Nato, has rejected a number of proposals put forward by Moscow for the missile shield to be built in co-operation, including the request for a legal guarantee that the system's offensive capabilities, supposedly to counter the threat from "rogue states", would not be used against Russia.
"But so far we have failed to get a satisfactory reply on any of the options. It seems to us that for the US, the establishment of a missile defence system is a kind of set philosophy, an equivalent of Marxism-Leninism, not subject to revision or even questioning" he said.
"Our position is clear, we do not want to give Nato an opportunity to shoot down any missiles from the Middle East over our heads. We do not want someone to organise another Chernobyl."
Mr Rogozin said that early next year Nato will formulate the so-called architecture, or design, of a missile defence system, "after which any negotiations will be meaningless. The Russian government is making intensive efforts to persuade our partners to start a serious discussion. Otherwise, there will be no alternative other than of researching and implementing a military-technical counter-argument". Mr Rogozin refused to elaborate on what this "counter-argument" would be, but held that Britain can help prevent a return to a Cold War confrontation.
He continued: "We believe that the UK is an influential country because of its very close alliance with the US. Russia and the UK were traditional historical allies in all the major wars of the 20th century, so we expect that Britain will take a responsible attitude in favour of finding speedy solutions to this crisis, and it is now a crisis."
During his visit, Mr Rogozin met Sir Peter Ricketts, the Prime Minister's national security adviser.