Richard Dearlove is in a lonely place. Arguing that Britain is at risk within the EU sets him against the most recent former chiefs of MI5, MI6 and GCHQ as well as every other NATO member and former NATO Secretary Generals. They have all made clear that Britain is stronger, safer and more secure remaining in the European Union.
Instead Sir Richard is joining the shrill voices of the Leave campaign by arguing that Turkish accession to the EU is the greatest threat we face. Their simplistic argument is that it threatens not just our security but our NHS. Again, they ignore the facts.
They ignore that Turkey first applied to join in the EU in 1987 and has completed just one of 35 criteria it must fulfil. At this rate Turkey is still a thousand years away from joining.
And the leave campaign forget that accession can be vetoed by any EU country, including the UK. They should listen to Boris Johnson, who said in March this year, "I think the chances of the Turks readily acceding to the European Union are between, you know, nil and 20%...that's just simply not on the cards." This has been echoed by David Cameron in recent days.
Their latest attack on the EU-Turkey visa agreement is equally misplaced. This will not impact on the UK. Britain is outside the Schengen passport-free area of the EU, so Turkish citizens continue to require visas to come to the UK. Despite the wild warnings of Sir Richard et al, this latest agreement between some EU countries and Turkey has no bearing on us.
Let's look at the facts. In practice, the agreement would allow Turkish citizens to travel to continental Europe 90 days at a time, within any 180-day period, for business, touristic or family purposes only. There is no right to live or work in the EU and it will not apply to the UK or Ireland.
Moreover, this arrangement is part of an EU-Turkey deal which sees illegal Syrian migrants who arrive in Europe relocated to Turkey. The benefit to us is both the removal of illegal migrants on the continent and the reduction of incentives for others to come, whether from Syria, Iraq or those already in Turkey. The European Commission has shown that the scheme is now working by dramatically reducing the flow of new arrivals. Even Richard Dearlove himself has said "the exodus has slowed."
Of course we have to tighten our security. That is why the UK has opted out of the EU's mandatory relocation system for migrants, putting pay to the idea that we don't control our borders. And that is why we must stay in the EU to continue to take advantage of EU intelligence-sharing arrangements.
But there is a bigger point. The only way to prevent illegal migration to the EU is through co-operation within the EU. International crises require responses of equal scope. We cannot shut up shop and pretend that issues like this, with its roots in Middle East instability, will go away.
The answer is to work with our allies to co-ordinate responses that work in our interests. An EU that is weaker as a result of our departure would not be better equipped to confront historic migration flows. A Britain that had diminished influence in the world, was absent from EU discussions on how to respond to the crisis, had reduced intelligence sharing and which was dealing with a domestic recession - as the IMF and Bank of England predict - would be in a weaker position to deal with this crisis.
I am in no doubt that, had the EU not been created, recent events would have prompted European nations to come together to find a co-ordinated response. In keeping with its history, Britain would seek a seat at the table. It is incongruous and flies in the face of any evidence to argue that we are best placed to confront global issues, whether migration or terrorism, alone.
Just like their policy proposal, the leave campaign are acting in isolation. The international diplomatic and security community are clear: the facts show Britain is stronger and safer in Europe.
Malcolm Rifkind is a former Foreign Secretary and Conservative MP