washington vote iraq minority kurds independence blow unite state spend years billions dollars live thousands troop try hold iraq together former u.s. officials policy experts say diplomatic drive forestall monday referendum fail persuade kurdish leaders unite state close middle eastern ally likely see fresh proof diminish american power say kurds rule semi-autonomous region within iraq since 2003 u.s.-led invasion topple saddam hussein consider result historic step generations-old quest state major setback say jam jeffrey former u.s. ambassador iraq senior fellow washington institute near east policy rob us argument u.s. keep iraq unite result unite state could find hard stop predominantly shi ite muslim iran fill vacuum leave islamic state defeat shi ite militias ally iraq syria elsewhere say moreover vote give kurdish leaders mandate negotiate independence region 8.3 million threaten ignite strife could hind u.s.-backed efforts stabilize iraq eliminate remnants islamic state isis similar group see considerable risk say u.s. official speak condition anonymity grave danger conflict dispute oil-rich city kirkuk ethnically mix kurdish-held areas pit iraqi troop iran-backed shi ite militias peshmerga kurdistan regional government krg u.s.-trained paramilitary force bloodletting could foreclose trump administration hop promote negotiations baghdad krg avert kurdish declaration independence say keep eye ball state department spokeswoman heather nauert say tuesday kind division right could potentially hurt iraq conflict also could halt u.s.-backed operations return home sunnis displace battle reclaim nearly caliphate islamic state declare 2014. still hopeful get people talk stuff rather something drastic say second u.s. official also request anonymity referendum condemn neighbor turkey iran fear embolden independence demand kurdish populations ankara tehran trade partner landlocked iraqi kurdistan threaten retaliation fuel fear could intervene militarily expectations u.s. say would recognize vote could use tie iraqi kurds persuade krg president masoud barzani cancel referendum exchange guarantee talk baghdad u.s. protect iraqi kurds rebel hussein 1991 gulf war americans midwife iraqi kurdistan say robert ford retire u.s. diplomat middle east institute think tank serve deputy ambassador iraq kurds move ahead vote sign american credibility much less use u.s. bid stop referendum fail experts say part age barzani see fulfil aspirations independent kurdish state legacy moreover say peter galbraith former u.s. diplomat tie kurdish leaders trump administration mistakenly think barzani could weather backlash cancel referendum white house demand 10 days hold astonishingly inept diplomatic initiative ever see galbraith say former ambassador jeffrey say administration also fail account iran grow influence one thing push kurds direction fear iraq come domination iran shi ite militias say underlie problem iraq shi ite party baghdad want share power sunni arabs kurds kurdish independence vote damage u.s. efforts preserve unify iraq