Spain is willing to support a separate Scotland and it wants Gibraltar back. So says the Guardian. It states:
Spain has said it would not veto an attempt by an independent Scotland
to join the EU, in a boost to Nicola Sturgeon’s campaign for a second
independence referendum and the clearest sign yet that Brexit has
softened Madrid’s longstanding opposition. Alfonso Dastis, the Spanish foreign minister, made it clear that the
government would not block an independent Scotland’s EU hopes, although
he stressed that Madrid would not welcome the disintegration of the UK.
As for Gibraltar, again the Guardian,
Theresa May
would be prepared to go to war to protect Gibraltar as Margaret
Thatcher once did for the Falklands, former Conservative leader Michael
Howard has suggested, in comments that were immediately criticised as
inflammatory. Lord Howard’s suggestion that the prime minister would be ready to
follow in the footsteps of her predecessor 35 years ago came alongside a
government pledge to protect the sovereignty of Britain’s overseas territory.
First, Scotland by itself really is not much. A golf course and sheep, lots of sheep. If Northern Ireland also leaves, it has three options. First, go alone. Like that would work. Go with Scotland. Now frankly all the Protestants were sent from there by Cromwell so if you think the Troubles were bad just wait. Go with Irish Republic, and live with Catholics. The latter may ironically be the safest.
Now as for Spain, remember Elizabeth I. But now Britain has a wimpy Navy. But Spain has nothing! Spain most likely could not raise ferry fare to get to Gibraltar.