On March 3, 2006, Secretary of the Army Francis J. Harvey approved a Ground-based Midcourse Defense (GMD) manning model. This multi component unit is led by dual status Army National Guard commanders who serve on active duty while retaining their duties and responsibilities under their respective state National Guard.

The unit itself is composed of active Army Soldiers and Army National Guard Soldiers, who transition between full-time National Guard duty in Title 32 Active Guard and Reserve, or AGR, status.

Established in 1636, the militia and its successor the National Guard were established to defend the nation. Similarly, the GMD units, located in Colorado, Alaska and California, were created to protect the nation from limited intermediate and long-range ballistic missile threats to the United States.

Neither the National Guard nor the multicomponent concept, however, figured in the initial anti-ballistic missile, or ABM, defense manning concepts. The Safeguard ABM system of the 1970s was manned by regular Army personnel.

Later in the 1980s, emphasizing that "the systems must be able to perform its' mission with the personnel on duty at any given time without benefit of warning, recall or sequential Defense Condition, or DEFCON, alert status change," this command developed a variety of ballistic missile defense systems manning models.

While the 1987 report provides a number of options depending upon deployment concept, no mention was made of assigning responsibility outside the regular Army.

The origins of the multi-composed organization are actually more contemporary and can be traced to the 1990s, the end of the Cold War and the subsequent Army drawdown and restructuring.

As early as 1990, with the decreasing Communist threat and an increasing federal deficit, Secretary of Defense Richard Cheney proposed a plan to cut the Armed Forces by 25 percent during the next five years to be accompanied by a restructuring of the services. For the active component Army, the specified reductions involved "a drop in personnel strength from 770,000 to 520,000 and a cut in divisions from 18 to 14 by 1995."

Combined with the decisions of the Base Realignment and Closure Commission, the Army gradually shifted from a large forward positioned force to a U.S. based power projection force.

In 1991, following the Gulf War, the Army saw a distinct shift in its missile defense mission. With the Missile Defense Act of 1991, the Department of Defense was to "aggressively pursue the development of advanced theater missile defense." The goal was to deploy these systems by the mid-1990s.

At the same time funds for national missile defense were reduced as the DoD was to develop a cost effective, operationally effective and Anti-Ballistic Missile Treaty compliant missile defense system to be deployed at one site by 1996.

Following the dissolution of the Soviet Union and the Warsaw Pact in 1991, the internal analysis would go further. In May 1993, Secretary of Defense Les Aspin announced that with the end of the Cold War, the United States was no longer threatened by a massive attack from the Soviet Union. With regard to missile defense, the concern was now theater ballistic missiles controlled by third world dictators or "hostile or irrational states that have both nuclear warheads and ballistic missile technology that could reach the United States."

As Aspin noted that threat was here and now. The Clinton Administration's subsequent bottom up review evaluated defense strategy and provided long-lasting strategic and budgetary guidance. The review further reduced the active Army to ten divisions and laid out a national security plan for Fiscal Years 1995-1999 that required the military to support two major regional conflicts.

For missile defense, this meant a strategic realignment placing primary emphasis on theater missile defense, or TMD, rather than national missile defense, or NMD.

In March 1996, President Bill Clinton again reoriented the missile defense program, emphasizing those TMD systems designed to counter the existing short-range threat while deferring more advanced TMD systems until 2000.

In the same announcement, the president released the National Missile Defense "3-plus-3" Program. Under this initiative, missile defense organizations were given three years to develop the basic elements of a NMD system which could be deployed if need within an additional three years.

As Secretary of Defense William Perry explained, the administration, in the year 2000, would make the decision whether or not the threat warranted the deployment of the NMD. Although deemed significant, as the elsewhere in the DoD, funding and personnel for these efforts were reduced.

By the mid-1990s, the Army's personnel strength was actually at its lowest level since before World War II with 495,000 active duty personnel and 10 active divisions. Nevertheless, "the Army experienced a threefold increase in operational deployments."

The Army faced three established challenges: maintaining readiness, stabilizing its force and becoming more efficient. With the size of the active force declining, the National Guard and Reserve units saw an increase in mission requirements, while their numbers were declining too.

A Total Army Analysis identified mission shortfalls, which led to further restructuring within both the Active- and Reserve-components. At the same time, new strategies and structures -- Force XXI and Army After Next -- were developed to meet the evolving missions amidst on-going personnel and budget restrictions.

Anticipating the 3+3 decision in 2000, in 1998, the Force Development Integration Center of the U.S. Army Space and Missile Defense Command initiated meetings with the National Guard Bureau to discuss the then NMD manning issues.

At the same time a force design update was submitted to the U.S. Army Training and Doctrine Command to initiate the development process for a new unit to staff and deploy a future ground-based NMD system. By the end of the year, the National Guard had created a new force development officer, or FDO. Assigned to USASMDC, the FDO and the Planning Cell were to coordinate during the design and implementation of the NMD manning architecture.

By 1998, the Department of the Army historical summary reported that the Army National Guard made up 34-percent of the Army's total force structure with 55-percent of the Army's combat units, 46-percent combat support; 25-percent combat service support, 63-percent field artillery, and 46-percent air defense artillery.

The total force concept saw the increased integration of active and reserve units. For example, in fiscal year 1998 initiated a program to team Active component and National Guard divisions. These teamed units would train together and provide mutual support to accomplish common missions -- enhance training, digitization and deployability.

Future plans would take the concept one step further creating integrated Active component/Reserve component divisions. Similarly, the NMD FDO represented efforts to create coequal status within the force, the beginnings of a multicomponent unit. Even as efforts moved forward to create a multicomponent NMD unit, the Army's first such unit, the 32nd Air and Missile Defense Command was actually activated in 1999. The precedent was set.

Although the National Missile Defense Act of 1999 declared that "it is the policy of the United States to deploy as soon as is technologically possible an effective national missile defense system…," the road forward for NMD slowed in 1999.

Four criteria were identified to assess a deployment decision -- threat, cost, technological status and adherence to a renegotiated ABM Treaty. One year later President Clinton announced "I simply cannot conclude with the information I have today, that we have enough confidence in the technology … to move forward to deployment."

By late 2001, however, as President George W. Bush observed, the world was "vastly different" from that which created the 1972 ABM Treaty. By June 2002, the United States had formally withdrew from the treaty and prepared to deploy the Ground-based Midcourse Defense (GMD) system, for national missile defense.

An advocate of missile defense, Bush gave the Pentagon two years to have an interim operational missile defense system. The abrogation of the ABM Treaty expanded the available deployment locations beyond the Air Force's strategic missile sites and the national capital region.

Further change came at the end of 2002 with National Security Presidential Directive 23. In this document, which eliminates the distinction between national and theater missile defense, Bush stated that "our policy is to develop and deploy, at the earliest possible date, ballistic missile defenses drawing on the best technologies available."

Having determined how we will fight, the initial cadre for what would become the 100th Missile Defense Brigade (GMD) was organized in April 2003, with formal activation taking place in October 2003 at U.S. Northern Command Headquarters on Peterson Air Force Base, Colorado.

The 49th Missile Defense Battalion located at Fort Greely, Alaska, was subsequently activated on Jan. 22, 2004. In a series of organizational documents, the Chief of the National Guard Bureau formalized the multi component structure units with an effective date of Oct. 1, 2004.