A question from Yahoo! Answers:

It’s 50 years from now,fully independent Scotland needs it’s Defence Force sorted out………..?

………how many men would we need and what types for Scotland’s 1st defence force for ages?

Military planning is first and foremost an exercise in probability. Before you start pondering manpower needs, you need to figure out what operational duties the force will have to perform.

If, like Ireland, you believe that external threat (apart from poaching in the 200-mile zone and drug trafficking) is nearly non-existent, you can do quite nicely with next to no armed forces (Ireland’s army consists of three brigades with a total headcount of 8,500; there are also Naval Service and Air Corps, which bring the total headcount of the Irish Defense Forces up to 10,500).

If, like England, you have an imperial chip on your shoulder and/or spend too much time listening to the White House, there is no limit to what you can sink into the black hole called “defense”. British Army today has 107,730 active-duty members in Regular Army and 38,460 in Territorial Army; the total headcount for British Armed Forces is 180,690.

Another way to look at the problem is to figure out how much defense you can afford. Other European countries can provide a useful benchmark. Most EU countries maintain between three and five active service members per thousand people. For Scotland, with its current population of 5.1 million and likely 2050 population of 5.4 million, this translates into 15,000 to 25,000 troops…