Russia and the United States often appear to be at loggerheads. They feud over US plans to put missile interceptors in Europe near Russia's borders and Russian influence in former Soviet states.
These and other issues dividing Moscow and Washington are real conflicts of interest. But they overshadow a more positive development - real progress in nuclear arms cuts between the two powers that together hold 95 per cent of the world's nuclear weapons.
Since 1987, the US and countries of the former Soviet Union, chiefly Russia, have signed a series of disarmament treaties, reducing nuclear arsenals by about 80 per cent.
The Russian and US presidents recently agreed to reduce them further, by about a third. The new bilateral pact would replace the Strategic Arms Reduction Treaty, which expires on December 5.
As a result, the current ceiling on warheads would be lowered from 2,200 each, to between 1,500 and 1,675, and the number of long-range missiles from 1,600 each to between 500 and 1,100.
The explosive power of these arsenals is still enough to destroy civilised life many times over.
But the cuts are intended to stabilise strategic offensive forces at progressively lower levels, dissuade other countries with nuclear weapons (among them China, India and Pakistan) from expanding their warhead stocks and delivery systems, and help discourage the spread of nuclear weapons beyond the nine nations known to have them today.