
They use justice as their constituted policy to manage a world that is made almost entirely of ocean much easier. The main purpose of the Marines is bringing any criminal to justice, with a particular focus on capturing pirates. The duty of the Marines is to maintain a law and order throughout the world and impose the will and might of the World Government. It is also possible for a pirate to become a Marine if they have the recommendation of a Marine officer.
ALL USMC GENERAL ORDERS TRIAL
A former pirate may join the Marines if they undergo a trial and are pardoned for past crimes, such was the case for Jango. However, some pirates, such as Vergo, manage to join without the Marines realizing.

The Marines at the 153rd Branch in Shells Town had initially wanted to perform a background check on Koby. The Marines try to make sure that no pirates infiltrate their ranks. Notably, the orphans that Caramel had been planning to sell to the government all appeared to be under the age of ten. Non-canonically, the youngest known person to enlist is Zephyr, who joined at the age of fourteen. Canonically, the youngest known person to enlist in the Marines is Koby, who joined at the age of sixteen. It is currently unknown if there is minimum age requirement for joining the Marines. Another example is Kaidou the king of his homeland enlisted him in the Marines so that their kingdom could have a place at the Levely and because the kingdom could not handle him. Not all people who join the Marines do so willingly Mother Carmel was a human trafficker who sold children from her orphanage to the government to be trained as Marines. After enlisting, all Marines are assigned a unit, post, Marine code, and photo ID, which can be used to differentiate between fake Marines and the genuine article. There also seems to be no restrictions regarding race while a vast majority of Marines are human, they are known to also employ giants and (non-canonically) members of the Longarm Tribe. One can even enlist if the base they are enlisting at is outside their homeland, as seen when Koby enlisted at the base in Shells Town, even though he is from somewhere else. There also seems to be no restriction based on nationality. While a majority of Marines are seen to be male, there is also a good number of female Marines, including Tsuru, Gion, Hina, Tashigi, Isuka and formerly Bell-mère. There are no enlistment restrictions regarding gender. It appears that one simply needs to ask to join and a ranking officer, presumably the base commander specifically, simply needs to approve the enlistment. The exact process of joining the Marines is unclear. 9.8.2 Caribou's Kehihihihi in the New World.They are also antagonists in various non-canon material, such as the Warship Island, Goat Island, G-8 and Marine Rookie filler Arcs, the fifth and eleventh movies, and the third, sixth and tenth specials.

ALL USMC GENERAL ORDERS SERIES
Collectively, they stand as one of the Three Great Powers, alongside the Four Emperors and the Seven Warlords of the Sea, who were later replaced by the SSG.ĭue to their actions and role, they are one of the major antagonist groups of the series overall, specifically they serve as the main antagonists in the Romance Dawn, Loguetown, Enies Lobby, Sabaody Archipelago, Marineford, and Return to Sabaody Arcs. They maintain a presence on all of the world's known seas, through countless branch offices however, the vast majority of their forces are focused on the Grand Line, in which resides their base of operations, Marine Headquarters. The Marines are the seaborne military forces of the World Government, tasked with maritime law enforcement and naval warfare operations.
