Russia and the US have pledged to begin slashing their nuclear arsenals by up to a half during President Barack Obama first state visit to Moscow that started a day ago. Agreement on a December deadline for the start of decommissioning, expected to be imposed by this week when Mr Obama meet his Russian counterpart Dmitry Medvedev, will be hailed in both Washington and Moscow as a breakthrough in efforts to revive relations between the two Cold War rivals. Both countries claim currently to have about 2,200 missiles primed for deployment, with thousands more either in reserve or awaiting dismantlement.The declaration will allow both leaders to claim a foreign policy success. The two leaders also signed pacts allowing the transit of US military personnel and weapons through Russia to Afghanistan, restoring military-to-military ties, and pledging cooperation to limit the spread of nuclear materials.Obama sees this treaty as part of a larger nonproliferation effort that could lead toward the eventual elimination of nuclear weapons around the globe.