Updated March 17, 2020
Defense Primer: Geography, Strategy, and U.S. Force Design
World geography is an influence on U.S. strategy, which in
airspace surrounding Eurasia. Force elements associated
turn helps shape the design of U.S. military forces.
with this objective include, among other things:
World Geography and U.S. Strategy
 An Air Force with significant numbers of long-range
Most of the world’s people, resources, and economic
bombers, long-range surveillance aircraft, and aerial
activity are located not in the Western Hemisphere, but in
refueling tankers.
the other hemisphere, particularly Eurasia. In response to
this basic feature of world geography, U.S. policymakers
 A Navy with significant numbers of aircraft carriers,
for the last several decades have chosen to pursue, as a key
nuclear-powered (as opposed to non-nuclear-powered)
element of U.S. national strategy, a goal of preventing the
attack submarines, large surface combatants, large
emergence of regional hegemons in Eurasia. This objective
amphibious ships, and underway replenishment ships.
reflects a U.S. perspective on geopolitics and grand strategy
developed by U.S. strategists and policymakers during and
 Significant numbers of long-range Air Force airlift
in the years immediately after World War II that
aircraft and Military Sealift Command sealift ships for
incorporates two key judgments:
transporting ground forces personnel and their
equipment and supplies rapidly over long distances.
 that given the amount of people, resources, and
economic activity in Eurasia, a regional hegemon in
Consistent with a goal of being able to conduct sustained,
Eurasia would represent a concentration of power large
large-scale military operations in Eurasia or the oceans and
enough to be able to threaten vital U.S. interests; and
airspace surrounding Eurasia, the United States also stations
significant numbers of forces and supplies in forward
 that Eurasia is not dependably self-regulating in terms of locations in Europe, the Persian Gulf, and the Asia-Pacific.
preventing the emergence of regional hegemons,
meaning that the countries of Eurasia cannot be counted
Comparing U.S. Forces to Other
on to be fully able to prevent, though their own actions,
Countries’ Forces
the emergence of regional hegemons, and may need
The United States is the only country in the world that
assistance from one or more countries outside Eurasia to
designs its military to depart one hemisphere, cross broad
be able to do this dependably.
expanses of ocean and air space, and then conduct
sustained, large-scale military operations upon arrival in
Preventing the emergence of regional hegemons in Eurasia
another hemisphere. The other countries in the Western
is sometimes also referred to as preserving a division of
Hemisphere do not design their forces to do this because
power in Eurasia, or as preventing key regions in Eurasia
they cannot afford to, and because the United States is, in
from coming under the domination of a single power, or as
effect, doing it for them. Countries in the other hemisphere
preventing the emergence of a spheres-of-influence world,
do not design their forces to do this for the very basic
which could be a consequence of the emergence of one or
reason that they are already in the other hemisphere, and
more regional hegemons in Eurasia. The Trump
consequently instead spend their defense money primarily
Administration’s 2018 national security strategy document
on forces that are tailored largely for influencing events in
states that the United States “will compete with all tools of
their own local regions of that hemisphere. (Some
national power to ensure that regions of the world are not
countries, such as Russia, China, the United Kingdom, and
dominated by one power.”
France, have an ability to deploy forces to distant locations,
but only on a much smaller scale.)
Although U.S. policymakers do not often state explicitly in
public the goal of preventing the emergence of regional
The fact that the United States designs its military to do
hegemons in Eurasia, U.S. military operations in recent
something that other countries do not design their forces to
decades—both wartime operations and day-to-day
do can be important to keep in mind when comparing the
operations—appear to have been carried out in no small
U.S. military to the militaries of other nations. For example,
part in support 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
operations upon arrival in Eurasia or the waters and
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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

Countries have differing needs for military forces. The
United States, as a country located in the Western
CRS Products
Hemisphere with a goal of preventing the emergence of
regional hegemons in Eurasia, has defined a need for
CRS Report R43838, Renewed Great Power Competition:
military forces that is quite different from the needs of
Implications for Defense—Issues for Congress, by Ronald
countries that are located in Eurasia. The sufficiency of
O'Rourke
U.S. military forces consequently is best assessed not
CRS Report R44891, U.S. Role in the World: Background and
through comparison to the militaries of other countries
Issues for Congress, by Ronald O'Rourke and Michael Moodie
(something that is done quite frequently), but against U.S.
strategic goals, which in turn reflect U.S. policymaker

judgments about the U.S. role in the world.
Other Resources
Strategy Is a Policy Choice, Force Design
White House, National Security Strategy of the United States of
Is a Consequence
America, 55 pp., accessed August 6, 2018, at
The fact that U.S. policymakers for the last several decades
https://www.whitehouse.gov/wp-content/uploads/2017/12/
have chosen to pursue, as a key element of U.S. national
NSS-Final-12-18-2017-0905.pdf
strategy, a goal of preventing the emergence of regional
Department of Defense, Summary of the 2018 National Defense
hegemons in Eurasia, does not necessarily mean that this
Strategy of the United States of America, Sharpening the American
goal was a correct one for the United States to pursue, or
Military’s Competitive Edge, undated, released January 19, 2018,
that it would be a correct one for the United States to pursue
accessed August 6, 2018, at https://www.defense.gov/Portals/
in the future. Whether it would be a correct one for the
1/Documents/pubs/2018-National-Defense-Strategy-
United States to pursue in the future would depend on
Summary.pdf.
policymaker views regarding the two key judgments
outlined earlier. A decision on whether the United States

should continue to pursue a goal of preventing the
emergence of regional hegemons in Eurasia would then
Ronald O'Rourke, Specialist in Naval Affairs
influence U.S. military force design for the future.
IF10485




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


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https://crsreports.congress.gov | IF10485 · VERSION 10 · UPDATED

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