By Jonathan Beale
BBC News, Washington
There is a sense of pride, but also trepidation, for graduates and families
The US Marine Corps prides itself on being ready - even when the nation is not.
It calls itself the 911 branch of the US military - the first responders. And once again they're about to be thrust into the frontline.
Marines are already fighting in southern Afghanistan, but the president will soon order thousands more to follow.
Parris Island, South Carolina is where it starts for many. It's where raw recruits are transformed into America's elite fighting force. It's "boot camp" - the place where they say boys become men.
Parris Island is one of just two bases in the US that trains marines. At times it looks more like a military production line - with squads of recruits running, marching, or being put through their paces on various assault courses, everywhere you look.
This one base churns out 22,000 new marines every year. They're being prepared to fight in every condition.
In a massive swimming pool they learn to swim loaded down with helmet, kit and rifle. Those who don't manage to stay afloat are pulled out to swim another length of the pool.
Basic training takes 13 weeks. Those who graduate will be sent for specialist training and then to a combat unit. They could be in Afghanistan within months.
This is where raw recruits are fashioned into an elite force
The strenuous physical activity of boot camp is deliberately made hard. It can be all the more unpleasant because of the heat and mosquitoes of South Carolina.
And then there's the drill sergeants who scream at the recruits everywhere they go. First Sergeant Rafael Rodriquez says that the recruits are left in no doubt as to what to expect, adding that they're told that some of them will get killed.
The recruits themselves come from a variety of backgrounds. And they give very different reasons for signing up.
Matthew Decarli joined to escape a dead-end job as a fork-lift truck driver. He thinks the Marine Corps will open new opportunities.
John Smith from New Jersey wanted to become a marine ever since he was 10 - when he witnessed the events of 9/11 on television.
The recruits are being given a new identity. And proof of them taking on their new persona is their constant reference to themselves as "this recruit". They no longer talk about themselves in the first person - they're being trained to think and fight as a unit.
Sense of trepidation
What's happening in Afghanistan is never far from their minds. It's constantly in the news.
There are also the polls that show most Americans now think that the war is not worth fighting.
Joanne Ortiz-Gonzales from Puerto Rico says at first she tried to "blank it out". But now she says "this recruit is ready to serve her country". Parris Island is also the only base that turns women into US Marines.
The strenuous physical activity of the camp is deliberately difficult
Around 10% will never make the grade. So for those who do make the final graduation ceremony there is a sense of pride and achievement.
This is when they're finally reunited with their families who are allowed to witness the parade. But for the parents and grandparents who watch, there's a sense of trepidation.
One father tells me that he's naturally worried about his son being asked to serve in Afghanistan. A grandfather of another recruit says he hopes that they'll be allowed "to fight to win".
As one group graduates another takes its place. And all of them now know that it will be the US Marine Corps who'll bear the brunt of the fighting.