(S (S (S (NP (BASENP (DT The) (ADJP (RB historically) (JJ close)) (NNS relations)) (PP (IN between) (NP (BASENP (NNP Canada)) (CC and) (BASENP (DT the) (NNP U.S.))))) (VP (VBD was) (ADJP (JJ evident) (PP (IN during) (BASENP (DT the) (JJ recent) (NNP Virgin) (NNP Atlantic) (NN incident)))))) (COMMA ,) (SBAR (WHADVP (WRB where)) (S (BASENP (DT a) (NN flight)) (VP (VBD was) (VP (VBN intercepted) (PP (IN by) (BASENP (NN 2) (JJ Canadian) (NNP CF-18) (NN jet) (NNS fighters)))))))) (PERIOD .))