LIBERAL-DEMOCRACY – peace, order, good government, human rights and the rule of law – are moral ideals. In a world where fallen nature corrupts all things, the Russian invasion of Ukraine reminds us that such ideals cannot be realised by words alone.

Sometimes – when greed, ambition or ­paranoia drives rulers into aggression, when the lie that they are “only defending their own ­borders” is exposed by seizing the territory of others, when sovereign countries are carved up and swallowed – our freedom must be bought at a sacrificial price.

This is not a call for further escalation, ­merely a recognition that Ukraine has “skin in the game” on the front line of the fight for freedom, and that we betray our own freedom – and our own values – if we betray their cause.

The only acceptable response to threats against the “free and civic way of life” ­cherished by all democratic nations is steadfast ­solidarity – a defiant, disciplined, courageous unity, standing in unbroken line, hand-in-hand and shoulder-to-shoulder, from the Baltic to the Black Sea.

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After the Second World War, the ­precious ­freedom so grievously lost and dearly ­restored had to be defended by a new ­international ­order. This brought together Western ­democratic countries in a firm alliance based not only upon shared interests, but upon shared ­values, a shared repudiation of the horrors of ­totalitarianism which had so nearly obliterated the freedom of European nations.

After the Soviet Empire fell, the newly ­liberated half of Europe rushed to join the ­Western alliance – not out of any compulsion, but because they too embraced the values of liberal-democracy and realised, in the words of an old song, “in each loss or triumph, lose or ­triumph all”.

Do not be deceived. Nato does not exist to threaten Russia, but to keep democracy safe from threats.

Some commentators have suggested that these resurgent threats to freedom weaken the case for Scottish independence – that the world is too dangerous a place for an independent Scotland to survive. Not at all.

The threat posed by international aggression merely reinforces the need for an independent Scotland to be a strong, resilient and ­dependable state, which is willing and able to fully ­shoulder its share of the collective burden of keeping the West free. We must reassure domestic and ­international audiences that Scotland will be a good neighbour and a strong, reliable ally.

One of the first tasks of a post-­independence Scottish Government will be to conduct a ­Strategic Defence Review, based on a frank, hard-headed, reckoning of threats and ­capabilities, priorities, risks and costs, in order to set the shape of the Scottish armed forces in the decade to come.

However, there is useful preparatory work to be done now.

We should start with a better informed, more engaged, public debate on the options for ­defence and foreign policy after ­independence. This will better enable us to prepare for ­negotiations with London on the initial ­distribution of ­defence ­assets, the use of bases, and the transfer of personnel, and will help to build the necessary cross-party and public consensus for longer term foreign policy, defence and procurement decisions.

We are still some way from having that ­conversation. The SNP has worked hard to gain confidence and credibility on defence, but a deeply ingrained anti-military sentiment – forged by justified moral outrage at nuclear weapons and opposition to the Iraq war, ­persists on the left wing of the wider Yes movement.

Meanwhile, those who do think seriously about defence are, for the most part, either staunchly Unionist or deeply ignorant of ­Scottish affairs. That leaves a gap in our public discourse.

It is necessary to consider Scottish defence in the widest sense, and in its broadest ­relationship with the whole “grand strategic” orientation of the state.

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In a harmonious and stable state, there has to be congruence, at the most fundamental ­levels, between the nature of the state itself, its ­economic system, its foreign policy, and its ­defence policy. In other words, defence policy is an instrument of foreign policy, and ­foreign ­policy is an instrument of domestic and ­economic policy, and all of these stem from the character and principles of the state itself, ­expressed in its constitution.

This is where the UK is weak. Building a bigger navy is well and good, but the UK’s credibility in the defence of Western values is strained by the rottenness of its internal politics.

It is hard to resist the ­arrogance of bullies, oligarchs, populists and ­authoritarians when Boris Johnson is your Prime Minister, when the governing party is awash in illicit roubles, when several bills ­crippling democracy are being rammed through parliament, and when you do not have a solid constitutional foundation to rely upon.

Scotland can do better. We need a strong ­defence capability firmly rooted in liberal-democratic constitutional foundations, so that we can defend freedom with the strength that comes only from moral integrity.

Ivan McKee MSP is next week’s guest on the TNT show. Join us on IndyLive at 7pm on Wednesday