(S (S (S (BASENP (NNP Ukraine)) (VP (VBD threatened) (S (VP (TO to) (VP (VB bar) (NP (BASENP (JJ Russian) (NNS warships)) (VP (VP (VBN dispatched) (PP (TO to) (BASENP (DT the) (JJ Abkhazian) (NN coast)))) (PP (IN from) (S (VP (VBG returning) (PP (TO to) (NP (BASENP (PRPD their) (JJ Ukrainian) (NN base)) (PP (IN of) (BASENP (NNP Sevastopol))))))))))))))) (SBAR (IN if) (S (BASENP (PRP they)) (VP (VBP engage) (PP (IN in) (BASENP (DT any) (JJ military) (NN action))))))) (PERIOD .))