All they need to support is a Treaty of Union which would give the Scottish nation a proper equality inside the United Kingdom. Under this regime aspects such as defence could be agreed jointly, for, after all, the loyalty of troops is, at least nominally, to the Crown.
It is also becoming clear that England will be increasingly at a loss without Scotland, owing to our resources of fossil fuel, water and renewable energy, so the formation of a balanced UK is in everybody's interest.
Perhaps the Tories could form a pact with the well known federalists the Liberal Democrats.
Iain WD Forde
Causewayend Main St