As we flounder through the novichok morass without a jot of evidence, these crimes should be treated as they remain, local cases of attempted murder. They should be detached from global power plays, political grandstanding and penalty shootouts. They belong to the Wiltshire police and their advisers.
If nothing eventually emerges to implicate Moscow in the poisonings, more fool the politicians. If they were indeed a Russian plot, then the time to get justifiably angry is when this has been proved. Until then, I recommend the tennis.