Updated November 15, 2022
Defense Primer: Geography, Strategy, and U.S. Force Design
World geography is an influence on U.S. strategy, which in
structured with force elements that enable it to deploy from
turn helps shape the design of U.S. military forces.
the United States, cross broad expanses of ocean and air
space, and then conduct sustained, large-scale military
World Geography and U.S. Strategy
operations upon arrival in Eurasia or the waters and
Most of the world’s people, resources, and economic
airspace surrounding Eurasia. Force elements associated
activity are located not in the Western Hemisphere, but in
with this objective include, among other things:
the other hemisphere, particularly Eurasia. In response to
this basic feature of world geography, U.S. policymakers
An Air Force with significant numbers of long-range
for the last several decades have chosen to pursue, as a key
bombers, long-range surveillance aircraft, and aerial
element of U.S. national strategy, a goal of preventing the
refueling tankers.
emergence of regional hegemons in Eurasia. This objective
reflects a U.S. perspective on geopolitics and grand strategy
A Navy with significant numbers of aircraft carriers,
developed by U.S. strategists and policymakers during and
nuclear-powered (as opposed to non-nuclear-powered)
in the years immediately after World War II that
attack submarines, large surface combatants, large
incorporates two key judgments:
amphibious ships, and underway replenishment ships.
that given the amount of people, resources, and
Significant numbers of long-range Air Force airlift
economic activity in Eurasia, a regional hegemon in
aircraft and Military Sealift Command sealift ships for
Eurasia would represent a concentration of power large
transporting ground forces personnel and their
enough to be able to threaten vital U.S. interests; and
equipment and supplies rapidly over long distances.
that Eurasia is not dependably self-regulating in terms of Consistent with a goal of being able to conduct sustained,
preventing the emergence of regional hegemons,
large-scale military operations in Eurasia or the oceans and
meaning that the countries of Eurasia cannot be counted
airspace surrounding Eurasia, the United States also stations
on to be fully able to prevent, through their own choices
significant numbers of forces and supplies in forward
and actions, the emergence of regional hegemons, and
locations in Europe, the Indo-Pacific, and the Persian Gulf.
may need assistance from one or more countries outside
Eurasia to be able to do this dependably.
Comparing U.S. Forces to Other
Countries’ Forces
Preventing the emergence of regional hegemons in Eurasia
The United States is the only country in the world that
is sometimes also referred to as preserving a division of
designs its military to be able to depart one hemisphere,
power in Eurasia, or as preventing key regions in Eurasia
cross broad expanses of ocean and air space, and then
from coming under the domination of a single power, or as
conduct sustained, large-scale military operations upon
preventing the emergence of a spheres-of-influence world,
arrival in another hemisphere. The other countries in the
which could be a consequence of the emergence of one or
Western Hemisphere do not design their forces to do this
more regional hegemons in Eurasia. The Biden
because they cannot afford to, and because the United
Administration’s October 2022 National Security Strategy
States is, in effect, doing it for them. Countries in the other
document states: “The United States is a global power with
hemisphere do not design their forces to do this for the very
global interests. We are stronger in each region because of
basic reason that they are already in the other hemisphere,
our affirmative engagement in the others. If one region
and consequently instead spend their defense money
descends into chaos or is dominated by a hostile power, it
primarily on forces that are tailored largely for influencing
will detrimentally impact our interests in the others.”
events in their own local regions of that hemisphere. (Some
countries, such as Russia, China, the United Kingdom, and
Although U.S. policymakers do not often state explicitly in
France, have an ability to deploy forces to distant locations,
public the goal of preventing the emergence of regional
but only on a much smaller scale.)
hegemons in Eurasia, U.S. military operations in World
War I and World War II, as well as numerous U.S. military
The fact that the United States designs its military to do
wartime and day-to-day operations since World War II (and
something that other countries do not design their forces to
nonmilitary elements of U.S. national strategy since World
do can be important to keep in mind when comparing the
War II), appear to have been carried out in no small part in
U.S. military to the militaries of other nations. For example,
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
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Defense Primer: Geography, Strategy, and U.S. Force Design
sustained, large-scale military aircraft operations upon
strategy, a goal of preventing the emergence of regional
arrival in distant locations.
hegemons in Eurasia, does not necessarily mean that this
goal was a correct one for the United States to pursue, or
As another example, it is sometimes noted, in assessing the
that it would be a correct one for the United States to pursue
adequacy of U.S. naval forces, that U.S. naval forces are
in the future. Whether it would be a correct one for the
equal in tonnage to the next several navies combined, and
United States to pursue in the future would depend on
that most of those several navies are the navies of U.S.
policymaker views regarding the two key judgments
allies. Those other fleets, however, are mostly of Eurasian
outlined earlier. A decision on whether to continue pursuing
countries, which do not design their forces to cross to the
such a goal would then influence U.S. military force design
other side of the world and then conduct sustained, large-
for the future.
scale military operations upon arrival in distant locations.
The fact that the U.S. Navy is much bigger than allied
CRS Products
navies does not necessarily prove that U.S. naval forces are
CRS Report R43838, Great Power Competition: Implications for
either sufficient or excessive; it simply reflects the differing
Defense—Issues for Congress, by Ronald O'Rourke
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.)
Other Resources
White House, National Security Strategy, October 2022, 48 pp.,
Measuring the Sufficiency of U.S. Forces
accessed November 15, 2022, at https://www.whitehouse.gov/
Countries have differing needs for military forces. The
wp-content/uploads/2022/10/Biden-Harris-Administrations-
United States, as a country located in the Western
National-Security-Strategy-10.2022.pdf.
Hemisphere with a goal of preventing the emergence of
Department of Defense, 2022 National Defense Strategy of
regional hegemons in Eurasia, has defined a need for
the United States of America, Including the 2022 Nuclear
military forces that is quite different from the needs of
Posture Review and the 2022 Missile Defense Review, cover
countries that are located in Eurasia. The sufficiency of
letter dated October 27, 2022, 80 pp., accessed November
U.S. military forces consequently is best assessed not
15, 2022, at https://media.defense.gov/2022/Oct/27/
through comparison to the militaries of other countries
2003103845/-1/-1/1/2022-NATIONAL-DEFENSE-STRATEGY-
(something that is done quite frequently), but against U.S.
NPR-MDR.PDF.
strategic goals, which in turn reflect U.S. policymaker
judgments about the United States’ role in the world.
Strategy Is a Policy Choice, Force Design
Is a Consequence
Ronald O'Rourke, Specialist in Naval Affairs
The fact that U.S. policymakers for the last several decades
IF10485
have chosen to pursue, as a key element of U.S. national
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Defense Primer: Geography, Strategy, and U.S. Force Design
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