Why are European partners nervous about Russia's return to diplomatic talks with the US?

European partners are nervous because of the remarkable diplomatic turnaround Russia has experienced. As John Simpson explains, just days ago, Russia under Vladimir Putin was 'out in the cold' diplomatically, but suddenly they're not only back at the negotiating table but positioned 'in the center' of discussions with the US Secretary of State. This dramatic shift represents an 'amazing turnaround' in Russia's diplomatic standing, essentially elevating their position from isolation to direct engagement with America. European allies likely fear this bilateral engagement might sideline their interests or concerns, especially regarding the Ukraine conflict and broader European security matters.