I've read a very interesting theory that the entire Alabasta plot is just being used as a distraction to hide the real objective which is wrecking Fishman island and kidnapping Shirahoshi.
- Reverie went far to great for the Fishman don't you guys think ?
- And Shirahoshi, as an ancient weapon, just walking into the holy land and leaving safely is suspicious to me.
The Gorosei + Im regard Vivis family as traitors, so taking Cobra out while attacking Shirahoshi is catching two birds with one stone.
The entire attention will be put on Vivi, Revolutionary's and straw hats, and after Fishman island is wrecked the government can easily say that they currently didn't even have the resources for attacking the Fishman since they're after Warlords/unknown alabasta incident etc.
Everybody is dancing to the God king Im-samas master plan