By Andrew Osborn and Mark Trevelyan MOSCOW (Reuters) – Seated at a large white table in an echoing Kremlin hall, Vladimir Putin summoned his top security officials one by one on Monday to give him their advice at a potential turning point in the crisis around Ukraine. In a lengthy meeting of his Security Council, broadcast on state television in what a presenter called “unprecedented footage”, Putin cross-examined ministers and spy chiefs on the question of whether to recognise the two breakaway Donbass regions of eastern Ukraine as independent states. One after another, they walked to a white…