I'm not sure that last week's First Ministers Question Time did a lot to reassure Scots the nation is in sound hands.

Labour's Johann Lamont and Nicola Sturgeon, standing in for Alex Salmond who was in China, turned the indignation meter up to 11 in a finger-jabbing confrontation my granny would have called a stair-heid rammy. As the leader-in-waiting of the SNP, Sturgeon should learn from Salmond to speak softly and carry a big stick. Her argument was undermined by failing to address the issue directly while accusing others of bullying and blackmail.

People are naturally worried by episodes such as Grangemouth and Govan, where agencies outwith the control of the Scottish Government appear increasingly to drive economic events. At Grangemouth it was Ineos and uncompromising boss Jim Ratcliffe; at Govan it was the Royal Navy's procurement policies, founded on the principle that Britain does not commission complex warships from foreign yards, for the obvious reason that the MoD doesn't want its most closely guarded military secrets to be shared with foreign governments, however friendly.

Sturgeon never quite got to grips with this, insisting British ships had been built abroad and there had been collaboration with countries as varied as South Korea and Australia. That may be true for run-of-the-mill vessels, but hi-tech craft like Type 26 frigates are invariably kept in-house. It was natural therefore that this would be Labour's main line of attack on the Scottish Government last week. They would ask: why should the UK Government, after independence, buy ships from Scotland, a foreign land?

In fact, the answer came from UK Defence Secretary Philip Hammond himself when he announced the closure of Portsmouth's shipbuilding facilities. He could not have given the go-ahead for Govan had he not accepted the possibility that Scotland might become independent. He was asked repeatedly if he would consider cancelling the Type 26 orders after a Yes vote in next year's referendum and repeatedly he refused even to contemplate it. There is a very obvious reason why.

If BAE Systems, a private firm, was in any serious doubt about the contracts, it would not be pouring money into Govan and Scotstoun, and nor would the Government. BAE has run down its shipbuilding at Portsmouth and consolidated activities in Scotland not for political reasons, but for commercial ones: Scotland builds better and cheaper. It is almost impossible to see circumstances in which the orders would be now be cancelled, whatever the outcome of the referendum.

A Yes vote, remember, will not make Scotland independent overnight. There will be an 18-month transition period before Scotland becomes legally independent of the UK in 2016. The contracts will therefore be signed while Scotland is still part of the UK, which also means EU procurement rules do not come into play. Somehow this important fact got lost in last week's media storm.

Scottish voters have been left with the impression that if they vote Yes, they lose the Clyde - which is unfortunate to say the least. Certainly, Sturgeon has a right to be annoyed with Alistair Carmichael, the Liberal Democrat Scottish Secretary, who came close to saying what Hammond would not: that the orders would be cancelled if Scotland votes Yes in September 2014. The Labour MP Ian Davidson went further and actually called for a wrecking clause to be placed in the Type 26 frigate orders such that they would automatically be cancelled if Scotland opts for independence. With friends like that …

Fortunately, the UK Government wasn't having any of it. Hammond does not want another procurement scandal on his hands so soon after the disaster of the current aircraft carrier contracts, now costing twice the original estimates. Imagine if next year he told BAE that, after all, he wanted them to dismantle Govan and Scotstoun and transport the skills and technology to redundant Portsmouth? The cost would be immense. It would be like moving the second Forth Road Bridge two miles up river after the foundations have been laid.

So, has the Govan issue frightened Scottish voters contemplating independence? It well might have, because the good news for Govan got lost in the sheer clamour of media voices declaring the yard doomed if Scotland votes Yes. Invariably these were Scottish-based commentators, rather than English ones. In fact, Hammond played the issue fairly straight by refusing to issue such warnings or endorse the gloomy scenarios of Carmichael and Davidson. But coverage in the Scottish media was uniformly negative, with the BBC's David Porter insisting he was told "privately" the Clyde yards would certainly close if Scotland voted Yes.

The Scottish Government had a very strong case here, but it rather went by default. Granted, no-one was expecting this announcement to come last week. Conspiracy theorists might think it was timed to hit the headlines when Salmond was in China, a shipbuilding rival. In fact, it was the premature removal of Govan cranes, not the removal of the First Minister, that brought the announcement forward.

But Salmond would probably have handled it rather differently. Instead of bluster, he would simply have declared victory - as he did in the 2007 Holyrood election - and defied anyone to challenge him.

The future of Govan, he would have said, is no longer a referendum issue, as it might have been had the closure of Portsmouth not been decided until after September 2014.

The UK Government relied on the tribalism of Scottish politics and the willingness of anti-nationalist politicians to trash their own nests to create a climate of uncertainty around Scottish ship-building at the moment it had won the security that eluded the Clyde for decades. There was an inability to recognise Scotland had won, for a change. Perhaps it is a kind of industrial defeatism: Scotland has got so used to industrial closures we expect them.

There is a parallel here with the Grangemouth petrochemical plant. The dispute there should never have been allowed to become a closure issue, and in allowing it to, the unions involved seemed to follow a 1980s script in which the workers always go down to heroic failure.

The fact that the First Minister's reputation was very much on the line in Grangemouth was another factor. Had the plant closed, he would have been attacked for allowing a large part of Scotland's industrial infrastructure to be sacrificed on the altar independence.

I'm not saying Labour or Unite wanted Grangemouth to go under - that would be ludicrous - but nor did they go the extra mile. The rivalry between Scotland's political parties has become a national liability. The truth is that for some politicians right now, uncertainty is good, crisis is good. They hope Scots will be discouraged from seeking independence because of the risk that the litany of closures would continue: Grangemouth no more, Govan no more, Scotstoun no more.

But these are dangerous political games. They'd better hope they don't get what they wish for.