AS the symbolic ending of the Cold War was recently celebrated in the 30th anniversary of the fall of the Berlin Wall, senior figures in the SNP are right to raise the prospect of the scrapping of Trident once again (“Trident looms large over Labour and Sturgeon as decisions seem hard to come by”, The Herald, November 12).

Trident is a hangover from another era when the Iron Curtain existed and relations between East and West remained immersed in suspicion and fear. Despite Westminster claims that Russia is still an aggressive threat, the involvement of that country in our democracy through sizeable individual and collective donations to the Conservative Party as well as alleged interference in the 2016 referendum is proof that the field of foreign affairs has altered significantly.

Trident is irrelevant in terms of modern national security where the real threats emanate from international terrorism and cyber attacks. The cost of renewing Trident at around £2 billion annually is not just unpalatable but unethical at a time of increasing poverty as witnessed by the increase in food bank use and people on zero-hour contracts.

The Conservatives, as is their dispiriting norm, choose to ignore SNP pledges to retain employment on the Clyde by increased spending on conventional defences, and hysterically claim that widespread unemployment will result from the scrapping of Trident, just as they do when trying to defend the indefensible in other issues. It does not matter whether it is fox hunting, the retention of the Royal Family or selling Scottish-made weapons to Saudi Arabia, the Conservative Party will seek to vindicate their immoral stance by offering a plea of job creation as justification.

Trident is obsolete in today's world and no amount of scaremongering or ineffectual rhetoric can disguise this fact. An independent Scotland would relocate Trident to somewhere down south, save £200 billion and direct spending towards addressing 21st century social and economic priorities.

Owen Kelly, Stirling.

GENERAL Sir Nicolas Carter, Chief of the Defence Staff, described Britain’s nuclear deterrent as an “insurance policy”.

I’ve just renewed by home and contents insurance policy. I pay my dues and forget about it. It’s only when my house goes up in flames that the policy becomes active on my behalf.

Now Trident isn’t like that at all. Trident is supposed to be a deterrent. It exists in order to deter an enemy from attacking us. The enemy has to understand that attacking us will result in an inevitable and devastating response. Trident is like a grenade whose pin has been removed and which will detonate if it is cast. It is “locked and loaded”. When a previous Minister of Defence, Sir Michael Fallon, was challenged that Trident as a weapon of mass destruction could never be used, he replied that on the contrary Trident was being used every day, because it functioned as a deterrent every day. So let us suppose that, despite its existence, we are subjected to nuclear attack. This would signal the failure of Trident to act as a deterrent. Therefore a deterrent is the exact opposite of an insurance policy. For as long as my house is intact, my insurance policy is dormant. When the blow falls, my insurance policy kicks is and begins to work for me. But so long as we are not subject to nuclear attack, we may imagine our deterrent is working. When we are attacked, our deterrent ceases to work and demonstrates that it has never worked.

Trident qua insurance policy is a slipshod metaphor, a cliché. The greatest challenge facing humanity today is: how can we all get along together without destroying ourselves and the planet? And we don’t really think about it. Not really.

Dr Hamish Maclaren, Stirling.

MIKHAIL Gorbachev, the former Soviet leader, recently said: "All people have to clearly state – all people – that nuclear weapons must be destroyed. This way we will be saving ourselves and the planet." The world’s leading scientists agree. They have moved the Doomsday Clock forward to two minutes to midnight, and it now stands closer to extinction than ever before, even at the height of the Cuban missile crisis.

On July 7, 2017, 122 states at the UN agreed on the TPNW – the Treaty Prohibiting Nuclear Weapons. This must be our red line in the election. Not to vote for any candidate or party that defends Trident and does not support the TPNW. Fortunately, we in Scotland have a choice, as all parties supporting independence take a principled objection to all weapons of mass destruction. Shamefully, all the Unionist parties do not.

Brain M Quail, Glasgow G11.