Henry Kissinger, the pioneer of Cold War detente during the Nixon era, has made a return to front-line politics after US President Barack Obama reportedly sent him to Moscow to win support from Vladimir Putin's government for a nuclear disarmament initiative.
It is believed that the 85-year-old former US secretary of state met President Dmitry Medvedev for secret negotiations in December.
According to Western diplomats, during two days of talks Mr Kissinger courted Russian officials in an attempt to win support for Mr Obama's initiative, which could see Russia and the US each cutting their nuclear arsenals to 1,000 warheads.
Mr Kissinger is believed to have won a verbal rather than written undertaking for the deal.
Tom Graham, a senior associate at Kissinger Associates and a former member of the national security council in the White House, confirmed that Mr Kissinger had met Mr Medvedev but denied that any negotiations had taken place.
While the details of the initiative are yet to be revealed, the possibility of a return to negotiations after eight years of reluctance in Washington has been welcomed in Britain and elsewhere.
Mr Obama apparently chose Mr Kissinger for his consummate diplomatic skills and his popularity in Moscow, an affection earned by his open acknowledgment of Russia's international resurgence.
Despite his pariah status with many in the Democratic Party, the president forged relations with Mr Kissinger during his election campaign. The compliment was returned when the 85-year-old veteran of the Nixon and Ford administrations said last month that the president was in a position to create a "new world order" by shifting US foreign policy away from the hostile stance of the Bush administration.
Further demonstrating his willingness to work with his opponents on foreign policy issues, Mr Obama turned to two veteran Republicans steeped in Cold War experience to press home his plans.
Shortly after Mr Kissinger's trip, Richard Lugar, a Republican senator who has worked on nuclear disarmament issues for 30 years, also visited Moscow. George Schultz, another former secretary of state, has also played a role.
Observers say signs of progress towards a new treaty could come as early as this weekend, when senior government officials meet at a security conference in Munich.
Joe Biden, the US vice president, is expected to address the conference and diplomats hinted he could announce the suspension of plans for a missile defence shield in central Europe, a project that has been denounced in Moscow.
Despite widespread praise for the proposals, European officials are privately urging the US to be cautious, aware that Kremlin policy towards the West has been characterised by reversals.
Apart from worries over Russia's belligerent international policies, there is also little doubt a disarmament deal would benefit Moscow more than the US.
Russia has long called for a new deal to replace the 1991 Strategic Arms Reduction Treaty (START), which expires on December 5.
Under START, the Cold War adversaries agreed to halve their stockpiles to 5,000 warheads apiece.
An addendum negotiated in 2002 resulted in both sides cutting the number of warheads in service to between 1,700 and 2,200 each. (© Daily Telegraph, London)