washington republican foreign policy veterans outside experts warn suggestion republican presidential nominee donald trump might abandon nato pledge automatically defend alliance members could destroy organization help keep peace 66 years could invite russian aggression statements like make world dangerous unite state less safe senator lindsey graham south carolina trump critic one republican party lead foreign policy voice member senate arm service committee say statement thursday imagine ally nato particularly baltic state must feel read comment mr. trump 100 percent certain russian president putin feel happy man said.trump comment new york time interview would seem put page mr. putin richard armitage deputy secretary state george w. bush administration say interview reuters new york time interview trump response question potential russian aggression toward baltic state latvia lithuania estonia say moscow attack would decide whether come aid review whether nations fulfil obligations us add fulfill obligations us answer yes end nato robert hunter former u.s. ambassador alliance president bill clinton tell reuters essence nato single factor commitment unite state america security 27 members ask trump comment european union foreign policy chief federica mogherini say eu know need work defense capabilities say unite state need keep solidarity ally simple realize world today quite complicate one quite dangerous one need friends say mogherini speak washington carnegie endowment international peace letter sign bipartisan group 39 national security experts say trump inflammatory remark represent interest unite state strength alliances core interest say group include prominent republicans former homeland security secretary michael chertoff former state department official eliot cohen unite state must uphold north atlantic treaty organization commitments ally include poland estonia latvia lithuania letter say u.s. senator bob corker chairman senate foreign relations committee say mutual defense commitment essence atlantic alliance add republicans democrats become exasperate members alliance honor obligations military spend corker tennessee republican say statement respond trump suggestion decisions would depend part whether state attack meet financial commitments alliance former diplomat richard haass president council foreign relations say important see nato alliance solely budget term important net benefit u.s. derive stability security country region affect price u.s. would pay stability lose interest undermine haass tell reuters article washington treaty create nato 1949 call attack one member attack invoke help defend unite state attack sept. 11 2001. follow attack nato send awacs plan patrol u.s. sky 800 crew members 13 nato countries fly 360 sorties part eight measure approve support unite state nato three weeks late send elements stand naval force patrol eastern mediterranean monitor ship expand include entire mediterranean several months late nato official speak condition anonymity also note alliance deploy third troop afghanistan decade one thousand soldier non-u.s. nato ally partner give live still experts downplay trump comment even criticize kurt volker u.s. ambassador nato republican president george w. bush democratic president barack obama say inadvisable create doubt adversaries mind consequences would face invade country putin love volker say say general european attitude take trump pronouncements grain salt everyone know election campaign say trump nato plan would sharp break decades-long u.s. policy