In the past, global empires such as those of Rome or Britain or France could face attacks from anywhere across the empire.   Britain, for instance, fought Imperial wars in Southern Africa and Afghanistan.   The Internet takes us back to that situation – any country, no matter how small or obscure, potentially faces cyber espionage or incursions or attacks from people anywhere in the world.   Ask Estonia or Denmark, both small countries that came under attack from cyber attackers.
The Roman Empire never did manage to subdue the belligerent peoples in what is now Scotland.   How ironic, then, that Scots nationalists seem not to have realized that an independent nation will need to defend itself from global attack.   MP Rory Stewart has reminded them, asking some hard, clear-light-of-day, questions about the romantic, candle-lit, vision of Scottish independence.   Questioning Nicola Sturgeon, Scotland’s Deputy First Minister, who was appearing before the UK House of Commons Committee on Foreign Affairs, Stewart asked about independent Scotland’s plans for intelligence and security:

Sturgeon came under repeated pressure from the Tory MP for Penrith and the Border, Rory Stewart, a former army officer and Foreign Office diplomat, to explain how an independent Scotland would build, equip, train and fund its own spying and security services.
Stewart said the UK’s current annual spying and security budget did not include the total historic costs of building and equipping its intelligence services, from setting up secure intelligence units in overseas embassies, training its agents, to building and equipping GCHQ.
It would cost billions, he said, to set up the secure communications Scotland needed for its intelligence agencies. For instance, if an independent Scotland wanted to have the same number of embassies overseas as Ireland, which has 97, or Finland, which has 93, it would cost hundreds of millions to equip them.”