Was scrapping Nimrod a mistake, and is Poseidon an adequate replacement?
Short answerPoseidon is capable, but Britain should either have retained Nimrod longer or joined Poseidon earlier instead of accepting a long gap.
NotesThe P-8 Poseidon was expected to perform the maritime-patrol and anti-submarine mission effectively. The criticism concerns the transition rather than the replacement aircraft. Britain spent heavily bringing Nimrod MRA4 close to an operational standard and then retired the programme without an immediate successor. Entering the Poseidon programme earlier would have avoided a dangerous national capability gap.