Iceberg was a very approachable and exceptionally capable mayor.
First and foremost, he was a political creature. After his beloved teacher, Fisherman Tom, was executed by the World Government, he did not retreat but instead ran for mayor of Water 7. Then, using the political legacy his teacher had left behind—the Sea Train—he propelled himself into the mayor's seat.
The mayor of a city this large was practically equivalent to the ruler of a World Government-affiliated nation. Even the World Government had to show a measure of respect to the "king" of such a nation.
He could declare that he would not provide land for the Marines to station on, and so Water 7 had no Marine base.
He could declare that he did not welcome World Government officials, and so those officials had to ride the Sea Train from other islands again and again to communicate with him.
He could declare that the city had no need for an intelligence agency, and so CP9's agents could only lie low in silence, utterly stripped of the imposing presence they had elsewhere.
Only when they were leaving did CP9 regain some of their swagger, taking Franky and Nico Robin aboard the Sea Train under the escort of countless Marines.
Iceberg had always worked to keep the World Government out of this island. His political influence and popular reputation were more than enough to accomplish that.
In truth, the World Government normally could not be bothered with a "country" like this. Just as they did not particularly care who ruled Drum Island, they could not be bothered to care who served as Water 7's mayor.
But Pluton was different.
It was very different.
First, it had been built in Water 7 and had deep ties to the island. Second, it was an