Another thing to consider, which I forgot to mention last night, is that the starmer government had gone out of its way to reduce immunity against legal warfare for individual military personnel, with the intent that they can be left open to lawsuits and prosecution for actions they took under orders. This after starmer, in his previous career as a human rights lawyer, took part in civil prosecution of veterans in an attempt to punish them for following legal orders. He knows he can't send more than nominal defensive support to the middle east, because the rank and file will refuse to take part in anything that could later be construed as a human rights case or some sort of international law case. If he sent the qe2, or even just a destroyer to Aden, there's a non-zero chance the crew would mutiny.