Updated November 5, 2020
Defense Primer: Geography, Strategy, and U.S. Force Design
World geography is an influence on U.S. strategy, which in
operations upon arrival in Eurasia or the waters and
turn helps shape the design of U.S. military forces.
airspace surrounding Eurasia. Force elements associated
with this objective include, among other things:
World Geography and U.S. Strategy
Most of the world’s people, resources, and economic
 An Air Force with significant numbers of long-range
activity are located not in the Western Hemisphere, but in
bombers, long-range surveillance aircraft, and aerial
the other hemisphere, particularly Eurasia. In response to
refueling tankers.
this basic feature of world geography, U.S. policymakers
for the last several decades have chosen to pursue, as a key
 A Navy with significant numbers of aircraft carriers,
element of U.S. national strategy, a goal of preventing the
nuclear-powered (as opposed to non-nuclear-powered)
emergence of regional hegemons in Eurasia. This objective
attack submarines, large surface combatants, large
reflects a U.S. perspective on geopolitics and grand strategy
amphibious ships, and underway replenishment ships.
developed by U.S. strategists and policymakers during and
in the years immediately after World War II that
 Significant numbers of long-range Air Force airlift
incorporates two key judgments:
aircraft and Military Sealift Command sealift ships for
transporting ground forces personnel and their
 that given the amount of people, resources, and
equipment and supplies rapidly over long distances.
economic activity in Eurasia, a regional hegemon in
Eurasia would represent a concentration of power large
Consistent with a goal of being able to conduct sustained,
enough to be able to threaten vital U.S. interests; and
large-scale military operations in Eurasia or the oceans and
airspace surrounding Eurasia, the United States also stations
 that Eurasia is not dependably self-regulating in terms of significant numbers of forces and supplies in forward
preventing the emergence of regional hegemons,
locations in Europe, the Persian Gulf, and the Indo-Pacific.
meaning that the countries of Eurasia cannot be counted
on to be fully able to prevent, though their own choices
Comparing U.S. Forces to Other
and other actions, the emergence of regional hegemons,
Countries’ Forces
and may need assistance from one or more countries
The United States is the only country in the world that
outside Eurasia to be able to do this dependably.
designs its military to depart one hemisphere, cross broad
expanses of ocean and air space, and then conduct
Preventing the emergence of regional hegemons in Eurasia
sustained, large-scale military operations upon arrival in
is sometimes also referred to as preserving a division of
another hemisphere. The other countries in the Western
power in Eurasia, or as preventing key regions in Eurasia
Hemisphere do not design their forces to do this because
from coming under the domination of a single power, or as
they cannot afford to, and because the United States is, in
preventing the emergence of a spheres-of-influence world,
effect, doing it for them. Countries in the other hemisphere
which could be a consequence of the emergence of one or
do not design their forces to do this for the very basic
more regional hegemons in Eurasia. The Trump
reason that they are already in the other hemisphere, and
Administration’s December 2017 national security strategy
consequently instead spend their defense money primarily
document states that the United States “will compete with
on forces that are tailored largely for influencing events in
all tools of national power to ensure that regions of the
their own local regions of that hemisphere. (Some
world are not dominated by one power.”
countries, such as Russia, China, the United Kingdom, and
France, have an ability to deploy forces to distant locations,
Although U.S. policymakers do not often state explicitly in
but only on a much smaller scale.)
public the goal of preventing the emergence of regional
hegemons in Eurasia, U.S. military operations in World
The fact that the United States designs its military to do
War I and World War II, as well as numerous U.S. military
something that other countries do not design their forces to
wartime and day-to-day operations since World War II,
do can be important to keep in mind when comparing the
appear to have been carried out in no small part in support
U.S. military to the militaries of other nations. For example,
of this goal.
the U.S. Navy has 11 aircraft carriers while other countries
have no more than one or two. Other countries do not need
U.S. Strategy and Force Design
a significant number of aircraft carriers because, unlike the
The goal of preventing the emergence of regional hegemons
United States, they are not designing their forces to cross
in Eurasia is a major reason why the U.S. military is
broad expanses of ocean and air space and then conduct
structured with force elements that enable it to deploy from
sustained, large-scale military aircraft operations upon
the United States, cross broad expanses of ocean and air
arrival in distant locations.
space, and then conduct sustained, large-scale military
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Defense Primer: Geography, Strategy, and U.S. Force Design
As another example, it is sometimes noted, in assessing the

adequacy of U.S. naval forces, that U.S. naval forces are
equal in tonnage to the next several navies combined, and

that most of those several navies are the navies of U.S.
allies. Those other fleets, however, are mostly of Eurasian

countries, which do not design their forces to cross to the
other side of the world and then conduct sustained, large-

scale military operations upon arrival in distant locations.
The fact that the U.S. Navy is much bigger than allied

navies does not necessarily prove that U.S. naval forces are
either sufficient or excessive; it simply reflects the differing

and generally more limited needs that U.S. allies have for
naval forces. (It might also reflect an underinvestment by

some of those allies to meet even their more limited naval
needs.)

Measuring the Sufficiency of U.S. Forces
CRS Products
Countries have differing needs for military forces. The
United States, as a country located in the Western
CRS Report R43838, Renewed Great Power Competition:
Hemisphere with a goal of preventing the emergence of
Implications for Defense—Issues for Congress, by Ronald
regional hegemons in Eurasia, has defined a need for
O'Rourke
military forces that is quite different from the needs of
CRS Report R44891, U.S. Role in the World: Background and
countries that are located in Eurasia. The sufficiency of
Issues for Congress, by Ronald O'Rourke and Michael Moodie
U.S. military forces consequently is best assessed not
CRS Report R46336, COVID-19: Potential Implications for
through comparison to the militaries of other countries
International Security Environment—Overview of Issues and
(something that is done quite frequently), but against U.S.
Further Reading for Congress, by Ronald O'Rourke, Kathleen J.
strategic goals, which in turn reflect U.S. policymaker
McInnis, and Michael Moodie
judgments about the U.S. role in the world.
Strategy Is a Policy Choice, Force Design
Is a Consequence
Other Resources
The fact that U.S. policymakers for the last several decades
White House, National Security Strategy of the United States of
have chosen to pursue, as a key element of U.S. national
America, December 2017, 55 pp., accessed November 5, 2020,
strategy, a goal of preventing the emergence of regional
at https://www.whitehouse.gov/wp-content/uploads/2017/12/
hegemons in Eurasia, does not necessarily mean that this
NSS-Final-12-18-2017-0905.pdf
goal was a correct one for the United States to pursue, or
Department of Defense, Summary of the 2018 National Defense
that it would be a correct one for the United States to pursue
Strategy of the United States of America, Sharpening the American
in the future. Whether it would be a correct one for the
Military’s Competitive Edge, undated, released January 19, 2018,
United States to pursue in the future would depend on
accessed November 5, 2020, at https://www.defense.gov/
policymaker views regarding the two key judgments
Portals/1/Documents/pubs/2018-National-Defense-Strategy-
outlined earlier. A decision on whether the United States
Summary.pdf.
should continue to pursue a goal of preventing the
emergence of regional hegemons in Eurasia would then

influence U.S. military force design for the future.

Ronald O'Rourke, Specialist in Naval Affairs
IF10485



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Defense Primer: Geography, Strategy, and U.S. Force Design


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