Imperialism is the policy of a state by which control is established
beyond its borders over people generally unwilling to accept such control.
I know of three important works on imperialism. They were all written
(1902, 1917, 1919) in the wake of what has been known as The New
Imperialism (c.1875-1914). The 1902 work is IMPERIALISM, A STUDY by the
British economist John Atkinson Hobson. The 1917 work is IMPERIALISM, THE
HIGHEST STAGE OF CAPITALISM by Lenin. The 1919 work is the essay "The
Sociology of Imperialism" by the economist Joseph Schumpeter. The
chronological order of these three is also the increasing order of their
sophistication.

In Schumpeter's analysis, imperialism is not seen as a product of
capitalism, contrary to the analyses of Hobson and of Marxists such as
Lenin. Indeed, Schumpeter portrays imperialism as antithetical to
competitive capitalism. Modern imperialism is, in his analysis, an
artificial graft on the more natural competitive capitalism. Imperialism
is made possible in capitalist society by catalytic effects of residue
from earlier feudal, autocratic society. Imperialism breeds war.

Another capitalist writer against imperialism was Ayn Rand. In her
essay "The Roots of War" (1966), she writes: "A market conquered by war
can be of value (temporarily) only to those . . . [who seek to] acquire
special privileges by force. . . . Who justified such policies and sold
them to the public? The statist intellectuals who manufactured such
doctrines as 'the public interest' or 'national prestige' or 'manifest
destiny'."

"The actual war profiteers of all mixed economies were and are of that
type: men with political pull who acquire fortunes by government favor,
during or after a war." Rand recommends a book by Arthur Ekirch titled THE
DECLINE OF AMERICAN LIBERALISM (1955). She gives a glimpse inside, where
there is portrayed an opposition of imperialism and many of the values of
traditional liberalism. The spirit of imperialism is seen as "an
exaltation of duty above rights, of collective welfare above individual
self-interest, the heroic values as opposed to materialism."