munich u.s. republican senators plan introduce legislation impose sanction iran accuse violate u.n. security council resolutions test ballistic missiles act destabilise middle east u.s. senator say sunday think time congress take iran directly term do outside nuclear program senator lindsey graham member senate arm service committee tell munich security conference graham say republicans would introduce measure hold iran accountable action tensions tehran washington rise since iranian ballistic missile test prompt u.s. president donald trump administration impose sanction individuals entities link country revolutionary guard iran bad actor great sense word come region iran say want us treat differently stop build missiles test-firing defiance u.n. resolution write death israel missile mix message graham say iranian foreign minister mohammed javad zarif tell conference early sunday iran respond well sanction threats jam jones former supreme ally commander europe president barack obama first national security adviser tell separate event munich remain convince sanction persuade iran negotiate 2015 landmark deal six world power curb nuclear program sanction work iran would never come negotiate table without sanction jones say new form response properly utilize change behavior get people things otherwise do senator christopher murphy member senate foreign relations committee tell panel nothing prevent congress impose sanction beyond lift result 2016 nuclear agreement iran murphy democrat say back nuclear deal explicit understand would prevent congress take action iran outside nuclear issue go conversation proportional response murphy say refer iran missile test necessarily think go partisan division whether ability congress speak issue outside nuclear agreement murphy say unite state need decide whether want take broad role regional conflict make decision whether go get involve emerge proxy war big way today iran saudi say senators look new sanction iran missile development