IF people don’t believe Nicola Sturgeon’s concerns about Brexit’s threat to security, they should at least pay attention to the head of MI6, the Lord Advocate and senior police officers, all of whom have expressed similar fears.

Of course, the Brexiters press on regardless. convinced that it’s all some bluff by the nasty EU. Thereafter the good ship Britannia will just sail on as the mother ship with all others recognising their importance, if not their rightful position. In their dreams maybe, but not in the real world.

As a former Home Secretary, Theresa May must be more aware than most of the risks and consequences. UK policing, never mind British intelligence, has been deeply involved in Europol and other institutions over many years.

That, no doubt, was part of the reason for her speech last week in Munich when she was to have laid out the British position. Yet it proved to be as vacuous as her other contributions and as bereft of formal proposals as the banalities espoused by her Foreign Secretary.

But it is not a bluff nor is it as simple as just signing some concordat. It is extremely complicated and operates at many levels, not just in intelligence sharing. It’s about relationships within wider organisations, co-operation between agencies and even personal relationships formed between officers and agents. Yet its already being damaged, and that even before the UK formally leaves.

The harm will be significant,as the benefits for Scotland and the UK were substantial. It provided not just intelligence but co-operation across security and law enforcement. Built up over many years, it was added to and refined. Trust was established and mutual respect created. It no doubt wasn’t easy but, it worked and it worked well.

It’s a few years now since the dreadful murder of Moira Jones, whose killer was a Slovak national who had fled back home. When that was discovered by Scottish police, contacts were quickly made and assistance from Slovakian law enforcement was sought. It was speedily forthcoming and within a very short space of time the murderer was apprehended and brought back to Scotland for trial.

There was genuine appreciation by Scottish officers for their Slovak counterparts and I was asked to formally record that when several were over on a visit. It was a pleasure to do so; justice might not have been done, or certainly not as quickly, without them. The European arrest warrant invoked in this case and about which the Lord Advocate and police have expressed fears was vital. We must think about practical issues like that along with the wider co-operation and intelligence that was established.

Visiting Europol and other cross-border law enforcement agencies I was always impressed by the work done. By the time of my last visit the director of Europol was a former English officer showing the influence the UK had. Scottish officers were also located there, offering a conduit for action or information. The UK was at the heart of it and with the excellence of policing here, was more often central to it.

It wasn’t always like that and it didn’t just spontaneously happen. I remember as a lawyer dealing with the death of a Scot abroad, where co-operation between forces was difficult to say the least. Procedures were also archaic, involving “letters of interrogatories” and other mysterious legal processes to try to access what proved to be limited information.

Now all that is threatened, and that threatens us. Speaking to some officers who had been over at Europol a few months back, they advised that they were already feeling eased out with the fear that worse would follow. The closeness was gone and a closing down was happening.

Crime is global and the threat to security transcends national boundaries. Co-operation is therefore required, but it needs to be worked at. Arrogantly trumpeting vacuous noises helps not one bit. Simply signing a concordat or other piece of parchment is likewise inadequate. What worked here was being a central part of the institution.

Of course, the First Minister rightly didn’t comment that security being threatened was the third of the trinity of woes that were to befall Scotland had the independence vote been won in 2014. The Better Together campaign highlighted then the strength of sterling, the certainty over EU membership and the security afforded by remaining in Britain.

The reality now of course is that the pound has tumbled, we are exiting the EU and now even our security is being threatened. She was right not to bring that up, as that was then and this is now. It won’t, however, be forgotten when another opportunity arises.

However, Ms Sturgeon was correct to warn of the dangers posed, whilst Theresa May has been negligent in actions taken to date.