Alexei Navalny is tonight in custody in Moscow. The Russian opposition leader was arrested immediately on his return from Germany, which has demanded his release. It was in Berlin that Navalny was treated after he was poisoned with Novichok nerve agent in August. Russia denies attempting to kill the man who has become a thorn in the side of President Vladimir Putin. But Navalny's influence is gaining ground beyond Russia's borders since the attempt on his life in Siberia last summer. We take a closer look with our guests in The FRANCE 24 Debate.