hello, i'm christian fraser. you're watching context on bbc news. failures of leadership and judgment, a culture in which those with concerns felt unable to speak out, and a series events that should never have taken place. the senior civil servant sue gray delivers her verdict on the downing st parties — some of the behaviour she said is difficult to justify. the prime minister has apologised once again. i want to say sorry and i am sorry for the things we simply did not get right, and also sorry for the way that this matter has been handled. the uk warns of tough new sanctions for russia, while the us says moscow poses a threat notjust to ukraine, but to the international order.