LONDON (Reuters) – Russia might use chemical weapons in Ukraine in a “false flag” attack to provide a retrospective justification for its invasion, but there is nothing to suggest a broader use of such weapons in the war, a Western official said. “We think that chemical weapons could be used in a false flag attack to provide a retrospective justification for Russia’s invasion of Ukraine,” the official said on Friday. “The context that we’ve been looking at it in is from a false flag perspective. Clearly, whilst the Russians are highly likely to have a chemical weapons capability, there is noth…