Medvedev may or may not know this but Iran has ballistic missiles capable of hitting all of Europe. Russia can be a partner in deploying a defensive anti-missile system designed to counter this threat or it can return to a Cold War confrontational posture in which no one’s interests are served.
Russia sold those missiles to Iran and helped them develop their nuclear program.
Why does Medvedev/Putin ignore the fact that eventually Iran will turn on Russia? Have they forgotten Beslan? I am no Russia/Putin fan, but I do not wish on them another Beslan, or worse.