The one thing you never want to do is call a Marine a “soldier.” While to many civilians a person in a uniform carrying a rifle is always soldier, Marines and Soldiers in American have very different purposes and cultures.

First it’s important to realize that the U.S. Army is the largest service branch in the Armed Forces; by comparison, the Marine Corps is a minuscule organization. While the Army is certainly geared toward fighting and winning wars, it has a tremendous diversity of occupations and services that carry out a number of different missions.

Although the establishment of the Army and the Marine Corps both began during the Revolutionary War, their original missions were quite different. The Marines were established as sharp shooters for U.S. Navy ships. Often when two ships came close to each other, it was rifleman who could make a big difference by firing at enemy sailors. A company of Marines also made sure that any mutinies by sailors didn’t last very long.

The establishment of the U.S. Army under George Washington was aimed at building up a ground force with infantry, artillery and calvary elements in the model of the great European armies of France and Britain. The purpose of the Army was to defeat opponents in large scale conflicts and occupy territory.

Over the course of American history, Marines continued to serve alongside Sailors on Navy ships, but their talents as shock infantry troops was soon recognized. The Marine Corps gained international fame for their heroic fight against the Germans in the Belleau Woods of France during World War I. Not only did the Marines fight bravely, but they were savvy about promoting their efforts to the media. The American public ate up the stories about heroic “leathernecks.”

Although Marines and Soldiers are often used in very similar roles – as we’ve most recently seen in Iraq – Marines remain expeditionary troops who can sustain themselves in combat for short periods of time. In this capacity, Marines are used to hit the enemy fast and hard, turn them on their heels and allow larger elements from the Army to take over and exploit the opening in the enemy’s defenses.

Over the last eight years in the wars in Iraq and Afghanistan, the Marines has been used much like a mainline Army rifleman: deploying to a specific region for a tour of duty where they engage in policing and counter insurgency. The Marines have proved adept at the mission, but many worry that they have lost their expeditionary naval-based readiness.