BasicsIntelligence is a vital part of the side, but also something which can do more harm than good for your side if you do it badly. To carry out intelligence operations you need to have intelligence centres. 5 centres produce 1 agent per turn, more with the British bonus and various technologies. Your agents also need to be employed in the centres in order to be used, i.e. you can't simply train them and then demolish the buildings. Operations succeed based on the agent count of the attacker and defender where the offence rating of the attacker exceeds the defence rating of the other.
Protection (Awareness)
Intelligence protection is different from attack protection in that it doesn't get reset after a number of hours but instead ends when a player takes more turns or buys or sells more than twice on the swiss market. Gather intelligence doesn't contribute to awareness but other operations do. A territory can suffer 3 operations before it becomes in awareness.
List of Ops.
Gather Intelligence (1 Turn) - This is the most useful of the ops as it gives you the status screen of your target minus GNP and number of nuclear missiles.
Spread Propoganda (2 Turns) - Steals 10% of the target population. Useful to get back some population if you have had them missiled, but not very damaging to your target. Not recommended to use except on noobs who don't need intel pressure.
Poison Population (2 Turns) - Kills a percentage of your target's population. Not very useful as it only targets uneducated civilians. Not recommended.
Terrorism (2 Turns) - Damages the target's dynamic morale by 4%. In other words, the morale hit is only temporary. This is useful in conjunction with assassinate leader if a territory is struggling with morale and may revolt. However, a veteran player should still easily be able to avoid revolting unless the inteller manages to catch them very often. Conclusion, effective when used at the right time but useless and spammed around.
Bomb Enemy Agencies (2 Turns) - Destroys Intelligence Centres and some agents of the opponent. Potentially useful against other intellers early on in the game but only if there isn't another better op.
Bomb Banks (2 Turns) - Destroys 12% of the targets money. One of the most useful ops against EMP players who sell large amounts of units on the swiss market. Only use with values about 60 or so million in the early game and higher as it goes on.
Kill Educated Civilians (2 Turns) - Kills 12% of targets educated population. Another very useful operation used mainly against scientists between runs. Not worth using below 300,000 educated civilians and generally not at all against engineers since players with that many engineers will have money coming in which would be more useful to bomb.
Assassinate Leader (2 Turns) - Damages the target's dynamic morale by 12%. See Terrorism.
Frame Territory (2 Turns) - Frames a territory for a non existant attack. Entirely useless, don't even think about it.
Steal Technology (2 Turns) - Automatically researches one technology that you can research and your target has as long at it's not the last in the branch and it's not above sonar. Causes the attacker to 'gain a reputation for espionage' making it possible to only do this attack once every 150 turns. Useful early in the game with techless strategies to steal those vital researches from other players. Be careful not to do it on a big threat on the other side though since it does no harm to your opponent.
Take Hostages (2 Turns) - You leave some agents behind and ask for a ransom. The opponent can send in their special forces and you often lose all of your agents. Not good and not recommended except as a way to dump agents.