How to Introduce a Essay

I am evaluating significance, in Vietnam.
The question is How significant was guerrilla warfare as a reason for the USA's lack of success in Vietnam?

I was thinking somewhere along the lines of.

The Vietnam war was in a period of innovation and communist reconciliation, the war was drawn out, expensive and brutal. A combination of reasons can support the USA's shortcomings in Vietnam; implementation of guerrilla tactics, ineffectiveness of the USA's tactics, losing the hearts and minds of the South Vietnamese and the propensity of the Vietcong to take advantage of their environment.