As the Tokugawa shoguns had feared, this opening of the floodgates of Western culture after such prolonged isolation had a traumatic effect on Japanese society.
( ( As ( ( the ( Tokugawa shoguns ) ) ( had feared ) ) ) ( , ( ( ( this opening ) ( of ( ( the floodgates ) ( of ( ( Western culture ) ( after ( such ( prolonged isolation ) ) ) ) ) ) ) ) ( ( had ( ( a ( traumatic effect ) ) ( on ( Japanese society ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN As) (S (NP (DT the) (NNP Tokugawa) (NNS shoguns)) (VP (VBD had) (VP (VBN feared))))) (, ,) (NP (NP (DT this) (NN opening)) (PP (IN of) (NP (NP (DT the) (NNS floodgates)) (PP (IN of) (NP (NP (JJ Western) (NN culture)) (PP (IN after) (NP (JJ such) (JJ prolonged) (NN isolation)))))))) (VP (VBD had) (NP (NP (DT a) (JJ traumatic) (NN effect)) (PP (IN on) (NP (JJ Japanese) (NN society))))) (. .)))
The Tokugawa shoguns had feared that, because they understood the Japanese society very well.
( ( The ( Tokugawa shoguns ) ) ( ( had ( ( ( feared that ) , ) ( because ( they ( ( understood ( the ( Japanese society ) ) ) ( very well ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNP Tokugawa) (NNS shoguns)) (VP (VBD had) (VP (VBN feared) (NP (DT that)) (, ,) (SBAR (IN because) (S (NP (PRP they)) (VP (VBD understood) (NP (DT the) (JJ Japanese) (NN society)) (ADVP (RB very) (RB well))))))) (. .)))