While playing Civ II, I like to build large strategic defense lines to keep enemy units out of my territory. Only problem is that the only form of government where this isn't prohibitively expensive is Fundy. However, I have been trying out a few other methods with various results. The first method I've been trying, is what I call the Police State Gaurds. This method entails building a... well, a lot of Spys or Diplomats. You basically just get enough spies and sips to completely seal off your border, with no space between units for ZOC units to sneak through. And since Spy's and Dips cost no maintenance or happiness, you can build as many as you want. You still need a few forward bases though, for quick response, seeing as how a spy can't stop an oncoming armour column. The main purpose of this method isn't actually military defense anyways, it is designed to prevent espionage, exploration, and sneak attacks within your border. The second method is simply having a giant airforce, placed on airstrips at strategic points along your border, allowing you to scout out the area, brickwall enemy units with bombers, and make quick descisive strikes against the enemy before they can even reach you. In democracy, you're pretty much restricted to Stealth Fighters though... The third method I have come up with, is also to do with airstrips. You simply build airstrips at choke points in the middle of nowhere, where you can't post units for some reason. As soon as an enemy unit passes over the airstrip, it changes to the colour of that tribe, alerting me to who is violating my borders, and where they are, allowing me to send some units over there to deal with the situation as soon as it arises. *Note: this method only works on AI and really foolish humans. So, what are your critiques, queries, comments, and ideas aobut border defense?