LES Reid (Letters, November 22) asks why the Scottish Green Party wants to take Scotland out of the UK.

It is partly because there is much more chance of Green policies being implemented in an independent Scotland.

Westminster will not get rid of Trident.

Westminster will not adopt the policies required to combat climate change.

Westminster continues to erode the devolution settlement – even in areas where the powers are currently exercised by the EU and in the UK are devolved and, if Brexit happens, will go back to Westminster instead of to Holyrood.

And it is partly because decisions affecting our lives and destiny should be taken at the lowest level possible.

To support independence is not to be starry-eyed about the SNP. The SNP supports Nato membership. The SNP is willing to declare a climate emergency but without proposing policies that will respond effectively to that emergency. The SNP welcomes devolved powers to Holyrood but is centralist in its treatment of local authorities and communities.

Scotland staying part of the UK is part of the problem rather than enabling solutions.

David Mumford, Dunbar.

“BUT what does she mean by Yes?" asks Mark Smith (“Swinson was right to say yes to the nuclear question”, The Herald, November 22). Well, to me and most people yes just means yes. It means that Jo Swinson believes that being second to murder a million innocent people is somehow less wicked than being first. This is the inescapable logic of nuclear deterrence. It is not possible to believe in it and not be prepared to use the bomb, should deterrence break down. A conditional willingness to slaughter is no less evil for being conditional. It already devastates all moral limits. End of.

He asks rhetorically “Who on earth isn’t aware of the consequences of using nuclear weapons?” Well, Donald Trump for one said: “We’ve got ‘em, why not use ‘em?” And when the first Vanguard submarine arrived at Faslane, on radio I heard the captain explain excitedly :“With this thing we can hit any city in the world from anywhere."

The crews are not diligently training daily to not use the missile – they are training to use them. They’re just waiting for the order. The blind trust that it won’t actually be given is all that sustains them, Ms Swinson, and all believers in deterrence.

Mr Smith’s simple faith in deterrence is hideously misplaced. He clearly has no idea of the number of near accidental launches there have been. Let me recount just one incident. In 1962 during the Cuban Crisis, a nuclear-armed Soviet submarine B-59 was submerged in the Caribbean with a group of US destroyers and the aircraft carrier, USS Randolph above. B-59 was subjected to a barrage of depth charges, intended as a signal to surface. US forces were on Defcon 2, the highest state of alert before actual conflict. Taking these explosions as the opening shots in an attack, Captain Savitsky ordered the nuclear missile to be launched in retaliation. The Third World War had begun.

The launch key had three parts. The captain and second in command produced their keys. Vasili Arkhipov, another officer, disagreed. A quarrel broke out. Eventually, he persuaded the others against launching the nuclear missile. The sub surfaced, realised that was had not started, and sailed away. According to former US Defense Secretary Robert MacNamara, Officer Arkhipov “saved the world”.

Mr Smith should also check Stanislav Petrov “the man who saved the world”, and the 20 mishaps that might have started accidental nuclear war at www.wagingpeace.org. No one who knows these facts could possibly defend the lunacy of nuclear deterrence.Brian M Quail, Glasgow G11.

MICHAEL Kent (Letters, November 22) compares Nicola Sturgeon with Boris Johnson, stating that it is "scarcely possible to tell the difference between Ms Sturgeon and Mr Johnson". I would suggest to him that Scottish voters can totally tell the difference between a leader who believes that Scotland's future should be in Scotland's hands and a leader who believes that Scotland's future should be in his hands, and in the hands of a government Scotland hasn't voted for in more than 60 years. Mr Kent is wrong in suggesting that Ms Sturgeon will not commit to removing Trident from an independent Scotland and her concern about Jo Swinson's casual, one-word confirmation that she would press the nuclear button must be shared by millions of other horrified people throughout Scotland, the UK and beyond.

Mr Kent accuses Ms Sturgeon of personal attacks and that she has "never allowed cabinet decision-making to cloud the management of the SNP or the tactics or strategies used"; however as I very much doubt if Mr Kent has ever attended an SNP Government Cabinet meeting no reliance whatsoever can be placed on that statement, and in attacking Ms Sturgeon (the Scottish Politician of the Year) and her husband, Mr Kent is himself indulging in the personal attacks he complains about throughout his letter.

Ruth Marr, Stirling.

MY MP is Jo Swinson. I shall vote for her. My vote will be tactical. I shall be voting against the SNP candidate.

I regard the SNP as a continuing catastrophe for my beloved country, with current focus on the NHS. The other parties lack appeal, collectively mediocre on a good day.

William Durward, Bearsden.

Read more: Mark Smith: Jo Swinson had to say yes to the nuclear button question