cleveland republican presidential nominee donald trump say might abandon nato guarantee mutual defense would renegotiate scrap nafta trade deal elect draw fire senior republicans democratic rival response question potential russian aggression baltic state trump tell new york time washington would help defend nato members fulfil obligations us three baltic state estonia latvia lithuania former soviet republics nato members trump campaign manager paul manafort dispute quote say consistent candidate desire modernize unite state international treaties national security officials republicans say abandon nato mutual defense guarantee enshrine article treaty would abandon 66 years u.s. foreign policy threaten world powerful military alliance also weigh campaign democrat hillary clinton former secretary state trump likely opponent nov. election trump apparently decide america lack moral authority advance interest value around world clinton senior foreign policy adviser jake sullivan say statement senate republican majority leader mitch mcconnell tell cnn disagree totally trump comment nato important military alliance world history remain relevant today many americans know operation afghanistan nato operation mcconnell say add want reassure nato ally come defense member threaten u.s. senator lindsey graham south carolina former presidential rival trump say trump remark make world dangerous unite state less safe nato secretary-general jens stoltenberg say thursday would interfere u.s. election campaign ally solidarity key value group good european security good u.s. security nato head say statement unite state always stand european ally trump previously say would force ally shoulder defense cost unite state bear decades cancel long-standing treaties consider unfavorable redefine mean partner unite states.stoltenberg say defense spend among european ally canada rise last year first time many years 2016 say expect percent increase billion trade disputestrump rail nafta trade deal canada mexico u.s. job killer quote say new york time interview would prepare scrap could negotiate much good term unite state north american free trade agreement take effect 1994 administration president bill clinton husband hillary clinton unlike nato treaty u.s. laws appear give presidents significant authority renegotiate foreign trade deal without consult congress trade experts say trump president would enormous amount discretion say barry bosworth fellow brook institution former white house staffer elect trump could unilaterally terminate nafta free trade deal although court would likely decide president authority say gary hufbauer former deputy assistant secretary trade treasury department nafta enact law pass congress article 2205 agreement allow party withdraw deal six months notice hufbauer say u.s. court would likely allow trump make decision president lot power generally recognize say hufbauer currently peterson institute international economics washington think tank trump warn could end nato guarantee scrap nafta