than radars and sonars and so are sensitive to smaller Earth features. Indeed, the
spatial resolution of lidar from aircraft platforms can be less than a fifth of a meter.
Multispectral remote sensing is a clever way of overcoming the limitations of
use of various wavelengths. Multispectral remote sensing devices break bands
(continuous intervals) of wavelengths into several smaller bands of simultaneously
acquired data. Each band has its strengths and weakness for study of geographic
phenomena. For a given purpose, the most meaningful of these bands are numeri-
cally comanipulated so that they maximize information extraction from a satellite
or an aircraft sensor array. In recent years, work has been accomplished in hyper-
spectral remote sensing that simultaneously acquires data from tens of bands.Rimland Theory
A perspective ongeopoliticsand international relations, presented as a critical
response to theHeartland theoryproposed by J. Halford MacKinder. The Rimland
theory was the brainchild of Nicholas Spykman, a political theorist and professor of
international relations at Yale University. Spykman was a proponent ofrealismin
international relations, a view which holds that political states act solely to promote
their own interests and agendas. Writing in the 1940s at the height of World War II,
Spykman suggested that the Heartland theory put forth by MacKinder several dec-
ades earlier was flawed, in that it overemphasized the role of the Heartland in deter-
mining the balance of power in global relations. Spykman also drew heavily on the
writings of the American naval strategist Alfred Mahan in constructing his theory.
Although his academic training was not specifically in geography, Spykman consid-
ered the discipline to be of the utmost importance in analyzing and understanding
international relations and the dynamics of global power.
The Rimland theory appeared in Spykman’s 1944 bookThe Geography of the
Peace, published posthumously the year following his untimely death. He adopted
the basic spatial framework of the Heartland theory, but made some changes in ter-
minology. Spykman retains the concept of the Eurasian landmass representing a
“Heartland,” but calls the region that MacKinder labeled the “inner” or “marginal”
crescent the “Rimland.” He rejects MacKinder’s characterization of North and South
America, Australia, Japan, and Great Britain as lying in the “outer” or “insular”
crescent, and instead simply terms this region the “off-shore islands and continents,”
although he agrees with MacKinder’s view that for these countries sea power is of
paramount importance, and represents the main means of projecting power. In the
Rimland theory, the Heartland does not represent the pre-eminent seat of power that
it symbolizes in Heartland theory. Rather, it is the Rimland that is the foremost seat286 Rimland Theory