In the middle of the American presidential election campaign US-President Barack Obama told the Russian President Dimitri Medwedew that he would have “more flexibility” concerning the contentious problem of missile defence after the elections of November 2012. Thus, after his successful re-election, now - but also already known - options for overcoming the differences present themselves. If no agreement can be reached, NATO might be confronted with short-range missiles carrying nuclear warheads in the Russian exclave Kaliningrad in a couple of years, and the relationships with Russia, which are strained already, will presumably deteriorate. Further misgivings that an American-Russian arms race might develop are largely unfounded, but misgivings concerning possible consequences caused by mistrust are not. Cooperation in form of more intensive information exchange and a combination of capabilities would be the best way to overcome misunderstandings. A compromise would be another possibility, which could offer chances for a further disarmament of strategic and sub-strategic nuclear weapons. Which option the re-elected American president will choose is still open, but this decision will have to be made at the highest level with the Russian president Wladimir Putin. So in the following years a compromise could be agreed upon, which - instead of guarantees - could contain an agreement on cooperation, with regulations concerning both this cooperation and arms control. The Russian ideas, which components of a defence system could be limited to what extent, are wide-ranging. Possibly, however, it would be sufficient if Washington agrees to limit its verifiable number of interceptors. Afterwards Moscow could assess whether the capabilities of the missile defence system match with the declared aim or not. Thus, cooperation could develop pragmatically. Missile defence offers an opportunity to improve the relationships between NATO and Russia both in the long term and with a lasting effect. Indeed, thus the rules of the NATO-Russian relationships could be fundamentally restored. Whether this potential for cooperation will be used is still open. From a German and European point of view, enhanced cooperation in the sense of more transparency and confidence-building is wise and desirable. From an American perspective, however, if Moscow insists on maximum demands, cooperation could become even more difficult, even if Obama now has a certain flexibility concerning this problem. As in the negotiation process of the “New START” Treaty, personal engagement of both presidents will be required if significant progress is to be achieved.