Updated November 8, 2018
Defense Primer: Geography, Strategy, and U.S. Force Design
World geography is an influence on U.S. strategy, which in
Comparing U.S. Forces to Other
turn helps shape the design of U.S. military forces.
Countries’ Forces
The United States is the only country in the world that
World Geography and U.S. Strategy
designs its military to cross broad expanses of ocean and air
Most of the world’s people, resources, and economic
space and then conduct sustained, large-scale military
activity are located not in the Western Hemisphere, but in
operations upon arrival. The other countries in the Western
the other hemisphere, particularly Eurasia. In response to
Hemisphere do not design their forces to do this because
this basic feature of world geography, U.S. policymakers
they cannot afford to, and because the United States is, in
for the last several decades have chosen to pursue, as a key
effect, doing it for them. Countries in the other hemisphere
element of U.S. national strategy, a goal of preventing the
do not design their forces to do this for the very basic
emergence of a regional hegemon in one part of Eurasia or
reason that they are already in the other hemisphere, and
another, on the grounds that such a hegemon could
consequently instead spend their defense money primarily
represent a concentration of political, economic, and
on forces that are tailored largely for influencing events in
military power strong enough to threaten vital U.S.
their own local regions. (Some countries, such as Russia,
interests. The Trump Administration’s 2018 national
China, the United Kingdom, and France, have an ability to
security strategy document states that the United States
deploy forces to distant locations, but only on a much
“will compete with all tools of national power to ensure that
smaller scale.)
regions of the world are not dominated by one power.”
Although U.S. policymakers do not often state explicitly in
The fact that the United States designs its military to do
public the goal of preventing the emergence of regional
something that other countries do not design their forces to
hegemons in Eurasia, U.S. military operations in recent
do can be important to keep in mind when comparing the
decades—both wartime operations and day-to-day
U.S. military to the militaries of other nations. For example,
operations—appear to have been carried out in no small
the U.S. Navy has 11 aircraft carriers while other countries
part in support of this goal.
have no more than one or two. Other countries do not need
a significant number of aircraft carriers because, unlike the
U.S. Strategy and Force Design
United States, they are not designing their forces to cross
The goal of preventing the emergence of regional hegemons
broad expanses of ocean and air space and then conduct
in Eurasia is a major reason why the U.S. military is
sustained, large-scale military aircraft operations upon
structured with force elements that enable it to cross broad
arrival.
expanses of ocean and air space and then conduct sustained,
large-scale military operations upon arrival. Force elements
As another example, it is sometimes noted, in assessing the
associated with this objective include, among other things:
adequacy of U.S. naval forces, that U.S. naval forces are
equal in tonnage to the next several navies combined, and
An Air Force with significant numbers of long-range
that most of those several navies are the navies of U.S.
bombers, long-range surveillance aircraft, and aerial
allies. Those other fleets, however, are mostly of Eurasian
refueling tankers.
countries, which do not design their forces to cross to the
other side of the world and then conduct sustained, large-
A Navy with significant numbers of aircraft carriers,
scale military operations upon arrival. The fact that the U.S.
nuclear-powered (as opposed to non-nuclear-powered)
Navy is much bigger than allied navies does not necessarily
attack submarines, large surface combatants, large
prove that U.S. naval forces are either sufficient or
amphibious ships, and underway replenishment ships.
excessive; it simply reflects the differing and generally
more limited needs that U.S. allies have for naval forces. (It
Significant numbers of long-range Air Force airlift
might also reflect an underinvestment by some of those
aircraft and Military Sealift Command sealift ships for
allies to meet even their more limited naval needs.)
transporting ground forces personnel and their
equipment and supplies rapidly over long distances.
Measuring the Sufficiency of U.S. Forces
Countries have differing needs for military forces. The
Consistent with a goal of being able to conduct sustained,
United States, as a country located in the Western
large-scale military operations in distant locations, the
Hemisphere with a goal of preventing the emergence of
United States also stations significant numbers of forces
regional hegemons in Eurasia, has defined a need for
and supplies in forward locations in Europe, the Persian
military forces that is quite different from the needs of
Gulf, and the Asia-Pacific.
countries that are located in Eurasia. The sufficiency of
U.S. military forces consequently is best assessed not
through comparison to the militaries of other countries
(something that is done quite frequently), but against U.S.
https://crsreports.congress.gov
Defense Primer: Geography, Strategy, and U.S. Force Design
strategic goals, which in turn reflect U.S. policymaker
https://www.whitehouse.gov/wp-
judgments about the U.S. role in the world.
content/uploads/2017/12/NSS-Final-12-18-2017-0905.pdf
Department of Defense, Summary of the 2018 National Defense
CRS Products
Strategy of the United States of America, Sharpening the American
CRS Report R43838, A Shift in the International Security
Military’s Competitive Edge, undated, released January 19, 2018,
Environment: Potential Implications for Defense—Issues for
accessed August 6, 2018, at:
Congress, by Ronald O'Rourke
https://www.defense.gov/Portals/1/Documents/pubs/2018-
CRS Report R44891, U.S. Role in the World: Background and
National-Defense-Strategy-Summary.pdf.
Issues for Congress, by Ronald O'Rourke and Michael Moodie
Other Resources
Ronald O'Rourke, Specialist in Naval Affairs
White House, National Security Strategy of the United States of
IF10485
America, 55 pp., accessed August 6, 2018, at:
https://crsreports.congress.gov
Defense Primer: Geography, Strategy, and U.S. Force Design
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