A summit between the leaders of the world’s two nuclear superpowers no longer dominates the global stage as in the cold war.

However, Barack Obama, the US president, and Dmitry Medvedev, his Russian counterpart, still have much to discuss when they meet for the first time in London on Wednesday. They must do their utmost to ease the east-west tensions of the recent past. With much at stake in the economic crisis, the world cannot afford the distractions of avoidable political conflict between Washington and Moscow.