A diplomatic attack strikes fear in your enimies heart, scaring them that someone wants them gone. It also angers them that they where attacked,robbed, etc. It
fusturates them, for easyly imtimidated people, they will over produce troops,because they feel the need to defend themselfs and get revenge,this will cause them to
start bankrupting themsleves and spending all there recourses. Thats when you start making trade with them, take them under your advantage. Say stuff like "If you
give me [Recource or item you desire], I'll help you by sending [Item thats very abundant in your area, but only give them a little]" Thats how you take advantage
of there recources, and its how you conqure them, though they dont see you taking advantage, they see you trying to help them. But in reality, your taking more than
your giving, wich is a great way to make a large empire. People see diplomats as very usless units, but I see how effective they are. Of course, if your enemy is hard
headed and sees what your doing, you should constantly sabotuage them, rob them, and kill their commanders untill they have close to nothing (In this process, they
are likley to send troops, so have your defences up and ready, have troops as well as diplomats). Once they are in the stage when they have almost nothing, you can do
two things, 1.Do what you do when they are in the "close to nothing stage", start taking advantage of there needs, or 2.Threaten to attack them unless they give you
[Item you desire] so pretty much blackmail. Theese are great ways you can take advantage of towns, citys, or empires in your region.There are some risks your taking.
Your risking to get yourself compleatly domolished, if your enemy has a bigger Military or Diplomatic system, so try picking onguys your own size. If your really
heartless, people with smaller citys. If your a small city and you take on a legendary city, you probally know the outcome.But ifyour a small city and your taking
on another small city, or a village, you can expect a good outcome most the time. So know what your dealing with. I also suggest scouting them before you make a
decision to use your diplomats. Check there troops with scouts, check there buildings with agents/spies, then take and sabotuage.