https://crsreports.congress.gov
January 14, 2020
Defender 2020-Europe Military Exercise, Historical
(REFORGER) Exercises, and U.S. Force Posture in Europe
On October 7, 2019, the U.S. Army announced it would
conduct the largest U.S.-based exercise of forces deploying
to Europe in the past 25 years: Defender 2020-Europe.
While some have compared it to annual Cold War-era
REFORGER military exercises, the Army suggests that
while similar, Defender 2020-Europe will be a more
complex exercise than historical REFORGER exercises in
terms of logistics, multinational command and control, and
multidomain operations.
Defender 2020-Europe
From a military standpoint, in the event of a major conflict
on the European continent, present force levels, including
units in Europe as part of the “heel-to-toe” rotations, could
prove to be insufficient to defend U.S. and allied interests.
In that scenario, the United States may choose to flow
significant additional forces across the Atlantic, an
undertaking that would be complex under optimal
circumstances, and exponentially more so under conditions
of war, when an adversary might seek to actively prevent
the arrival of U.S. forces and equipment (“anti-access/area
denial”). Some officials are concerned that the United
States’ ability to move equipment in timely fashion, in
particular heavy tanks and fighting vehicles, from U.S.
bases to the ports from which the equipment is shipped
requires additional emphasis. Defender-2020 is intended to
exercise and test such expeditionary deployment
capabilities, much as REFORGER did in past eras.
What Was REFORGER?
REFORGER—REturn of FORces to GER many—was a
series of North Atlantic Treaty Organization (NATO)
annual military exercises conducted from the late 1960s to
early 1990s to validate the ability of NATO allies to rapidly
deploy forces to Europe to reinforce NATO positions on the
continent and to demonstrate Western commitment to
defend against Warsaw Pact aggression.
U.S. Military in Europe During the Cold War
While approximately 74,000 U.S. military personnel are
stationed in Europe today, at the height of the Cold War,
more than 400,000 U.S. military personnel were stationed
on the European continent. According to the Center for
Strategic and International Studies (CSIS):
In the late 1980s, the United States maintained
approximately 340,000 permanently stationed
military personnel in Europe to deter the
conventional threat that the Soviet Union and
Warsaw Pact forces posed to West Germany and
Western Europe. Of that, U.S. Army forces
represented approximately 193,000 soldiers
organized under two corps (each composed of an
armored division, an infantry division, and an
armored cavalry brigade) in addition to three
independent combat brigades and numerous enabler
and support units. Apart from permanent-stationed
forces, the United States maintained large
stockpiles of prepositioned equipment in Western
Europe—enough for several divisions and support
units—to allow forces based elsewhere to rapidly
reinforce the continent in the event of conflict.
The Evolution of REFORGER
According to the Government Accountability Office
(GAO):
REFORGER’S history can be traced to the 1967
Tripartite Agreement between the United States, the
United Kingdom, and the Federal Republic of
Germany. The agreement allowed the United States
to bring back to the United States the headquarters
and two brigades of the 24
th
Mechanized Infantry
Division, leaving only one brigade of that division
in Europe. To compensate for this reduction in
troop strength, the agreement required that U.S.
forces returning to the United States be held in a
high state of readiness to ensure their capability to
return rapidly to Europe in a crisis. The agreement
also stipulated that the 24
th
Mechanized Infantry
Division return the two U.S.-based brigades
annually to Germany, draw prepositioned
equipment, link up with the forward-deployed
brigade, and then participate in a field training
exercise (FTX).
