Germany’s sovereignty is limited, therefore one cannot expect full participation of its foreign affairs’ minister in international talks. Foreign and military policy of Germany is conducted under US supervision.
By urging Russia to destroy a missile system foreign affairs minister of Germany is playing a game: showing America that he is following the US political and informational line. In fact he does not care what will happen with the missiles, it is a long-term question. He understands that it is not necessary to go with the US in all directions – Nord Stream II is more important to Germany.