What is the author’s viewpoint in this excerpt? England’s demand for tea encouraged international cooperation.
England’s demand for tea caused conflict around the world.
Britain planted tea in China because Britain was at war with India.
Britain traded silver to buy tea, which resulted in high taxes.

England's demand for tea caused conflict around the world.

"The trade was so important that it brought the two countries to war. The first of the conflicts, which we still refer to as the Opium Wars - they were in fact just as much about tea - broke out more or less as our teapot was leaving the Wedgwood factory. "

it is an infinitive phrase with a subject.