[1/3] The Russian flag flies on the dome of the Kremlin Senate building, while the roof shows what appears to be marks from the recent drone incident, in central Moscow, Russia, May 4, 2023. REUTERS/Stringer Summary Incident is embarrassing but could be useful to Putin Kremlin sends message that Russia's existence is at stake Escalation could involve targeting Zelenskiy and team 'Terrorist' threat may provide pretext for more repression LONDON, May 4 (Reuters) - The humiliating spectacle for Russia of two drones flying over the walls of the Kremlin, its historic seat of power, has spawned conflicting theories about who...