Prepare translation of the main text
Maintaining the Force
The Armed Forces of the USA have undergone frequent large-scale deployments in different areas of the world for the last several years. To be able to do that they needed a well-trained professional military force. There are several sources of procuring personnel to the force: conscription, enlistment on voluntary or contract basis and joining the military through cadet corps.
There was conscription (also called draft) in the USA during the WWII. It was temporarily revived in the USA in the early 1970s at the time of the Vietnam War. 
The enlistment policy in the Army, as an example, is governed by Army Regulation (AR) 601–210 (Regular Army and Army Reserve Enlistment Program). This regulation prescribes eligibility criteria, policies, and procedures for enlistment and processing of persons, with or without prior service (PS), into the Regular Army (RA), Delayed Entry Program (DEP) and the U.S. Army Reserve (USAR). Besides it explains provisions for the release from Presidential Call, demobilization, and so forth. 
Persons who apply for enlistment in the RA or the USAR must meet eligibility criteria of this regulation and any other requirements for the Military Occupational Specialty (MOS) in which they are enlisting. Applicant is eligible for enlistment if he or she meets the following criteria: (1) specific test requirements of MOS or option for which enlisting. (2) Must have the ability to read, write, and speak sufficient English to understand the oath of enlistment and the Entrance National Agency Check (ENTNAC) Interview. Applicant is also eligible for enlistment if he or she meets procurement physical fitness standards of AR 40-501, Chapter 2 and meets added requirements of specific option for which enlisting.
Applicants must be from 17 to 35 years old, American citizens or registered aliens, and in good health and physical condition. To determine what careers they are best suited for, all applicants must take the Armed Services Vocational Aptitude Battery (ASVAB). The ASVAB is offered at most high schools and at Military Entrance Processing Stations (MEPS). Although the ASVAB has ten different subjects, it's the math and the verbal portion that determines whether or not the applicant passes the test. The other sections are designed to discover aptitudes for different jobs.
Today recruiting to the services is carried out mainly through recruiting offices but also through cadet corps.
Recruiting campaigns and publicity now emphasize the versatility and variety of professions and trades offered in the armed forces, rather than stressing a ‘macho’ image for the Army or luring volunteer to the Navy with the promise to travel to exotic places.
Enlistment in the RA is authorized for a term of at least 2 but not more than 6 years. A specific MOS may require a minimum term of service. Those applicants scoring 0-39 on the English Comprehension Level Test (ECLT) will be enlisted for 4 years regardless of MOS for which enlisting. Enlistment in the USAR will be for a period of 8 years.
Enlistment programs and options vary from time to time. Local Army recruiters always have the latest information and are ready to answer inquiries without obligation.