The Earth has its own standing military that is a member of the DOOP military. The Army is one of the most largest branches of the military, and is frequently used for both offensive and defensive operations. Like many of the militaries in DOOP, Earth's military seems to rely on brute force and advanced technology as its leaders suffer from incompetence.
Little is known about the Army's organization. It is unknown if it operates independently of the Navy. In certain situations, such as the invasion of Spheron I, Naval officers seemed to be in charge of the Army personnel, although this could just have been because of Zapp Brannigan's position of the head of Earth's military.
When necessary, the Army apparently trains troops in as few as one day. Training, at least under Zapp Brannigan's command, consists of physical training, weapon assembling, and jumping through flaming hoops.
Unlike the Navy, the Army has more traditional Earth dress and class B uniforms. Dress uniforms are khaki and display the wearer's rank the shoulder. Combat uniforms consist of an OD green BDU and armored shoulders, knees, and vest as well as a helmet with a crest on top that may or may not have an orange or black visor.
Troops are seen wielding different weapons in different episodes, but typically carry a laser rifle of one form or another. During the invasion of Spheron I, they were armed with Positron Shooters, which were charged by winding a handle that played a "Pop Goes the Weasel" tune.
The Army also has an assortment of vehicles based on the planet's terrain. Such vehicles includes includes hovercopters, hover-jeeps, and tanks.
The Earth's Army has been involved in several operations since 3000.
Earth declared war on the planet Spheron I for no apparent reason. Brannigan began the invasion by dumping his troops on the planet's surface without warning. They engaged the Spheres with mixed success. However, the war was won when a soldier, Bender, threatened to detonate a WMD unless the Spheres abandoned their planet.
Later, when the Army attacked the Decapodian embassy on Earth, the Decapodians responded by sending a large fleet of warships. Due to Zapp Brannigan handing Earth's defense codes to Decapodions, Earth was unable to mount any kind of defense and was saved only by an Earth loyal Decapodian, Zoidberg.
Earth also invaded Tarantulon 6 and easily defeated the native Spiderians. They then took the Spiderians riches, results in a $300 tax rebate to all Earth citizens.
According to the Chairwoman of DOOP, President Nixon invaded Da Nang 6 and keeps Earth from winning because he believes the war will be good for the economy.
Invasion of Spheron I Outcome: Earth victory
Defense of Earth from Decapodians Outcome: Earth defeat
Invasion of Tarantulon 6 Outcome: Earth victory
War on Da Nang 4 Outcome: Perpetual Stalemate