It's clear from the passage that trade ....... .

Imperialism is a national policy that favours
extending power or control over another country or
its colonies. Nations can expand by force, or by
peacefully absorbing another area. They may
extend their power by economic, political or military
means. Imperialism is as old as history. Ancient
Rome spread its laws, customs and language
throughout a large portion of the known world by
force. The great, empires of France, Spain and
England began through trade. To insure the security
of this trade, the so-called mother countries gained
political control of many territories and created
colonies all over the world. An imperialistic nation
might also lend money to another country and in
return get concessions, which may include having a
say in how, and by whom, the debtor country is
governed.