There was a time when a person from any country could become a US citizen by serving in the US Military. I don't know if this is still true or not. Check the web sites for the Army, Navy, and Air Force and/or call one of the recruitment offices which I am sure are listed on their web sites.
A Jamaican can join the US Army if they have a green card or they are a naturalized citizen.
no
A British citizen can join the US Army, and a British soldier might be attached temporarily to a US unit, or sent to a US training/instructional programme, but they won't be able to be in both services simultaneously.
Yes, you do need to be a US citizen
can a no legal status join the US army???
Yes.
nope you have to have a green card first or us citizen
Not even every US citizen living outside the US has to join the US army. Certainly people from other American countries do not have to.
Only a US citizen can enroll in the US military,you will need to become a citizen.
You have to be a US citizen to join the US marines i think its actually permanent resident
Define Work what kind of work? US citizen can not serve British army but can do work in commercially
No matter what country of origin, a non-citizen/ non-resident cannot join the US military without first gaining citizenship.Currently only US citizens are allowed to join the US Army. If a Jamaican has a green card, they may join the Army if they meet requirements.