Why was Philip Hammond, the Defence Secretary, accused of making threats or engaging in "emotional blackmail" in Scotland this week when he suggested Scottish jobs in the defence industry will be at risk if Scotland separates from the United Kingdom.

Mr Hammond was asked the question. He could have said: nothing will change if the UK is broken up, or I don't know if there will be consequences, or what he did say: that the Ministry of Defence will want to source its defence capability in its own indigenous base. That would be England, Wales or Northern Ireland. Therefore, the jobs would not go to Scotland.

Consider Mr Hammond's position from the point of view of anyone living in England, Wales or Northern Ireland. It is UK Government policy not to build warships in foreign countries, so what special case would he, or could he, make to give Scotland, or Scottish defence workers, preferential treatment? And, by the way, many working in the defence industry in the rest of the UK might have reason to complain already about jobs they had hoped or expected to go to them going instead to Scotland because Gordon Brown invested so much political capital in making sure they did.

So, yes, defence jobs in Scotland will be at risk if Scotland breaks away. That's not a threat or emotional blackmail but an injection of realism and common sense. And we don't need to wait and see to know. Even now, the MoD is holding back on the contracts to build the new generation of Type 26 destroyers on the Clyde until it knows the result of the referendum. Mr Hammond could not give a cast-iron guarantee on defence jobs in Scotland, principally because it would not be true.

Sir George Zambellas, the First Sea Lord, joined the debate this week. Much more in sorrow than in anger, he feared maritime security for everyone in the UK would be harmed if Scotland chose independence.

Hailing Scotland's historic role in the Royal Navy from the Battle of Trafalgar in 1805, when almost one-third of Nelson's men were Scots and five of his 27 ships were commanded by Scottish officers, to the present day, he said Scotland would face a deeper impact if it no longer had access to "one of the finest and most efficient navies in the world." When he says Scotland's claim on the Royal Navy would weaken greatly the carefully evolved entity as bases, infrastructure, procurement, spares, personnel and training faced a carve up, Nationalists simply say that would not happen. Yet Sir George cannot be written off as part of "unfounded attempts to whip up a threat to [defence] jobs."

Focus groups will say Scots don't like to be patronised or bullied or threatened (tell me who does) so we must conclude that is one of the reasons for the Nationalists' refusal to put forward coherent arguments, and bluff and bluster instead, to exploit any grievance, real or imagined.

Every argument from the pro-Union campaign is written off as scaremongering, or patronising, or bullying, or threatening, or part of Project Fear. The Scottish electorate deserves better from the Nationalist camp.

But perhaps another reason for the Nationalists playing the pantomine card ("oh, no you can't"; "oh, yes we can") is that they do not want to engage in serious debate on serious issues because they know they do not have the answers. Thus they rely on sentiment.

No matter how their arguments have been distorted, not one voice in the pro-Union camp believes Scotland could not go it alone. They believe, simply, that Scotland's prospects will be better and stronger if it remains part of the United Kingdom.

They are accused, wrongly, of patronising the Scottish electorate. It is not patronising to pose questions about the future of their country. And it is only right to tell defence workers, or any other workers, what the consequence of their vote might be. That is nothing whatsoever to do with scaremongering or patronising or bullying.

Scottish voters should go into the polling booth on September 18 knowing they could use the pound but not be part of a currency union; that energy bills will more than likely go up if Scotland breaks away; and that there will have to be border controls.