why doesn't the navy help with invasions

[swordshot]

Think as it as this, the navy hates BOTH of us. Jolly and us pirates. The Navy would help if it were the movie, because Elizabeth Swann is with the pirates and they have to make sure that she is un-touched. Elizabeth is inside the Governors Mansion, which is the target for the Port Royal invasions. So that is a hard question.... who would the navy want to die more? The pirates and Elizabeth, or Jolly Roger whom wants to destroy Elizabeth.... I dont understand the game- not like the movies at all..