One Piece World Government
The World Government is made up of 180 countries who run their own affairs but act together with the World Government when it comes to Foreign Policy. The Marines act as the fighting fist of this organization which is the largest power in the world. They claim to uphold truth and justice but the truth is that they themselves act on questionable motives and often cover up the truth just to keep the peace. The World Government will stop at nothing to keep order even if it means ignoring the rights of the very people they protect. Three famous examples of World Government cover ups are The Ohara Incident, Water 7 and Alabasta.
This event took place 20 years before the current time in One Piece. Professor Clover was telling the Five Elder Stars that a kingdom existed ages ago and its people wrote their history on huge blocks of stone named Poneglyphs. This civilization was wiped out 800 years ago by an unknown foe. It just so happened that the World Government was created around about this time and as this Lost History would be a thorn in the Government side, a Buster Call was called on the Island of Ohara.
Water 7 and the Blueprints of Destruction
Eight years before the current time in One Piece, the World Government made a move for the blueprints of Pluton, a weapon of awesome destructive power. They were under the care of Tom and his two helpers Cutty Flam and Iceberg in the city of Water 7. Tom was the shipwright who had built Gol D. Roger ship and to make up for his crime, had spent the last ten years creating a steam powered ship. When confronted by CP5 about the blueprints Tom claimed he never had them. The Leader of CP5 (Spandam) wasn't happy and planned to get him locked up as a criminal. On the day of Tom pardon the boat where Tom trial was taking place was attacked by boats made by Cutty Flam but under the control of CP5. Spandam told the court that Tom was a criminal but the shipwright asked weither he could have the crime he was just accused of pardoned instead. He didn't want to see Flam or Iceberg in chains. Cutty Flam staged a rescue attempt on the boat that Tom was whisked away on, only to be run over by it. The blueprints were in safe hands however as Tom had pasted them to Iceberg.
As soon as Crocodile was defeated by Luffy and his secret criminal group discovered, the World Government were quick to create a cover up. The World Government couldn't let people know that a pirate toke out one of the Shichibukai. They claimed that Captain Smoker and his aide Tashigi, took out the fiend and they both got promoted for it. Luffy on the other hand got his bounty raised to 100,000 000 beli for his trouble and Zoro bounty reached 60, 000 000 beli for his slaughter of 100 bounty hunters and Mr 1. As far as the World Government are concerned, they have two main aims. The first being to hide all knowledge of the Void Century and the second being the capture of pirates.
The Lost History, The Poneglyphs
The most serious crime in the World Government books is reading the Poneglyphs as they erased every single other snippet of information of the Void Century. If one can read these stones then they have the ability to call forth terrible weapons of destruction ones which the World Government wouldn't mind having themselves. Hence the reason for Nico Robin high bounty. Not even the world leaders have a clue about the information written on the stones. The only thing that is known about the Void Century is that a great race lost a war against an ancient enemy. This enemy could very well be the Five Elder Stars.
Anyone who raises the flag of conviction or declares that they are a pirate is instantly foes of the World Government. The Five Elder Stars are so concerned about the growing power of pirates that they even made a pact with a few that are now known as the Shichibukai. As the power of the Marines and the Pirates are about equal, the World Government will do anything to top a full on conflict between the two. There are a few pirates that worry the World Government the most. These are Monkey D. Luffy (due to defeating Sir Crocodile, ruining Enies Lobby and getting a crew member to set the World Government flag alight) and the Yonkou (Four Emperors). These four pirates rule over the latter half of the Grand Line like kings and a meeting between Whitebeard and Red Haired Shanks would be completely out of the question for the World Government.
The Five Elder Stars (Gorousei)
These five old men are at the highest tier of the World Government, outranking the Marines, Cipher Pol and the Shichibukai. They have the power to order Buster Calls and move whole fleets of Marines.
These pirates have had their bounties dropped and now work for the Government. They may only attack other pirates and give ten percent of the treasure they gain to the World Government. The Shichibukai were formed in order to combat a Marine vs Pirate war. There are seven members: Dracule Hawkeye Mihawk, Donquixote Doflamingo, Bartholomew Kuma, Jinbei (who has yet to make an appearance but is thought to be a Great White Shark Fishman) and two other as of yet unseen pirates. Sir Crocodile used to fill the seventh slot but as of the events of Alabasta, he has been dumped from the Shichibukai. Blackbeard has shown interest in this empty position.
CP9-Ciphor Pol Nine
There are nine Cipher Pol units, with each one acting as a kind of secret police and assassins from the World Government. CP9 (the most powerful Cipher Pol unit) are a secret one and have more powers than that of the others. They can use the rokushiki techniques (a group of six powerful skills that only CP9 know) and have recently been given the ability by Admiral Aokiji to order a Buster Call. CP9 are based in Enies Lobby\ Tower of Justice.