The "front line" in the U.S. Army refers less to a precise physical location than a general region where combat is likely to occur. The Army has infantry and armor divisions serving as its primary combat ground forces, which include Rangers and Special Forces teams that work behind enemy lines to subvert and destroy. Joining the front line is a matter of choosing the Military Occupational Specialty, or MOS, that gives you the greatest chance of getting into the fight. For any position, you must first take the Armed Services Vocational Aptitude Battery, which is a series of tests designed to help you understand your strengths and identify which Army jobs are best for you.

Infantryman

The most obvious and logical choice for front line duty is to join the infantry. Here, you'll engage the enemy directly -- sometimes hand-to-hand -- in efforts to actively clear positions and entrenchments. Infantry soldiers do the hard work, performing final cleanup duty. Infantry is also critical in building relationships with foreign locals and officials, hopefully making the infantryman's job easier by reducing or eliminating civilian resistance. Job training for infantry requires 14 weeks of One Station Unit Training, which includes Basic Combat Training and Advanced Individual Training. Part of the training takes place in the classroom and part in the field.

Armor

You can also serve in the front lines by joining armor divisions. These divisions often roll in ahead of infantry, taking out enemy tanks and ground defenses in advance. Armor also works as ground support with dismounted troops, serving to protect the troops from enemy vehicles and hard emplacements in buildings and bases. These soldiers also help transport ground troops to the field via quick fighting vehicles and troop transports. Job training for a M1 armor crewman requires 15 weeks of One Station Unit Training where you will learn tank operations, armor offensive and defensive tactics, map reading and other skills.

Special Operations

Special operations troops are engaged in front line activity and include Rangers and Special Forces. Rangers are part of quick-deploying fast strike raiding forces, securing critical areas such as airfields and munitions depots. Rangers also serve alongside conventional troops in supporting roles. Special Forces go in well in advance of the main invading force, eliminating key enemy leadership, putting in place friendlier factions in foreign governments and capturing key intelligence and personnel. Special Forces operate in small detachments and are often cut off from the bulk of main forces. There are a number of requirements to become a Special Forces soldier, including taking and passing the Army Physical Fitness Assessment and successfully completing the Pre-Basic Task list.

Attack Air Support

Aviation officers pilot Army helicopters such as the Black Hawk and Chinook. Although you'll take off from more remote locations, you will be in the line of fire as troops and anti-air stations attempt to shoot you down or disable your craft. Training for an aviation officer requires completing aviation school, where you study rotary-winged aircraft and basic flying skills.