've learned the hard way just how complex international terrorism is 
(ROOT (S (VP (VBP 've) (VP (VBN learned) (NP (DT the) (JJ hard) (NN way)) (SBAR (WHADJP (RB just) (WRB how) (JJ complex)) (S (NP (JJ international) (NN terrorism)) (VP (VBZ is))))))))
(ROOT (S (VP (VBP ) (VP (VBN ) (NP (DT ) (JJ ) (NN )) (SBAR (WHADJP (RB ) (WRB ) (JJ )) (S (NP (JJ ) (NN )) (VP (VBZ ))))))))