But isn't UK responsible for foreign affairs and defence? How does it work? Does Gibraltar need permission by UK to enter the Schengen area, for example? As for (re)joining the EU, I've heard it isn't possible because Gibraltar isn't a state.

Look upon the Daily Mail headline writer's work, ye mighty, and despair.

It's a negotiation between Spain and Gibraltar with the UK and the EU approving whatever it is they agree.

According to the Spanish constitution of 1978, Art. 63, the King, with prior authorization by the Parliament, has the power to declare war and make peace.

On elephants?

The UK and Gibraltar governments made clear on Monday that Schengen border checks by Spanish officials inside Gibraltar “would not be acceptable” as part of a treaty for the Rock’s post-Brexit relationship with the bloc, now or in the future.

In a joint communique issued after a whistle-stop visit by UK Foreign Secretary Dominic Raab to Gibraltar, both governments left no doubt this was a red line they would not cross.

It also says....

"In particular, the framework provides a pragmatic model to achieve the fluid movement of people between Gibraltar and the Schengen area. Under this model, a joint operation with the European Border and Coastguard Agency (Frontex) may thus be established for an initial implementation period of four years."

https://www.gov.uk/government/news/j...t-of-gibraltar

As Spain refuses to recognise Gibraltar this is going to be difficult. Spain has always insisted on bi-lateral talk with the UK and refused to enter into tri-lateral negotiations. They do not recognise that Gibraltarians have the right of self determination and insist on territorial integrity.

The agreement made at the end of last year included representatives from Gibraltar.

Deal between Spain and UK plans to eliminate Gibraltar border checkpoint

The tax agreement which has just been struck includes Spanish and Gibraltan tax authorities working together.

Spain to take Gibraltar off tax haven list after treaty enters into force

Represenatives (observers) not delegates. The deals are still between Spain and UK. Agreed local cooperation and cross border working arrangements but generally they do not touch on anything which could affect sovereignty.

Frontex is an EU agency, and would therefore not be 'Spanish officials' Gibraltarians can also apply to work for Frontex, as can any EU national.

UK government red lines . And that's why UK exports are now permanently screwed.... Gibraltar's next then.

Spain's position in any negotiations over Gibraltar have always been to accept any proposals that benefit Spain and to veto anything that may benefit Gib.
Never any give and take.

Looks like Spain also has red lines...

HMS Trent is now on it's way for it's deployment in Gibraltar.

A vaccine trial that was headed by a Gibraltarian physician in Scotland has resulted in a deal to manufacture 60 million doses in the UK.

Gibraltarian Physician Dr Roy Soiza is the principal investigator the Scottish trials of the Novavax Covid-19 vaccine.