1 3 , ▁if ▁it ▁chose ▁to ▁develop ▁one ., ▁and ▁that ▁US ▁intelligence ▁does ▁not ▁know ▁whether ▁Iran ▁int ends ▁to ▁develop ▁nuclear ▁weapons , ▁but ▁bel ieves ▁Iran ▁could ▁at ▁least ▁be ▁keeping ▁the ▁option ▁to ▁develop ▁them ▁open . ▁M oss ad ▁Chief ▁Me ir ▁D agan ▁was ▁more ▁c aut ious , ▁saying ▁recently ▁that ▁it ▁would ▁take ▁the ▁Iran ians ▁until ▁ 2 0 1 4 . ▁German , ▁French , ▁and ▁British ▁intelligence ▁said ▁that ▁under ▁a ▁worst - case ▁scenario ▁it ▁would ▁take ▁Iran ▁a ▁minimum ▁of ▁ 1 8 ▁months ▁to ▁develop ▁a ▁nuclear ▁weapon ▁if ▁it ▁chose ▁to ▁build ▁one , ▁and ▁it ▁would ▁have ▁to ▁first ▁pur ify ▁its ▁u ran ium ▁and ▁weapon ize ▁its ▁u ran ium . ▁An ▁anonymous ▁source ▁in ▁the ▁German ▁Foreign ▁Int elligence ▁Service ▁( B ND ) ▁whose ▁rank ▁was ▁not ▁provided ▁has ▁gone ▁further ▁and ▁claimed ▁Iran ▁could ▁produce ▁a ▁nuclear ▁bomb ▁and ▁conduct ▁an ▁under ground ▁test ▁in ▁ 6 ▁months ▁if ▁it ▁wanted ▁to ▁and ▁further ▁assert ed ▁that ▁Iran ▁had ▁already ▁master ed ▁the ▁full ▁u ran ium ▁en rich ment ▁cycle , ▁and ▁possessed ▁enough ▁cent rif ug es ▁to ▁produce ▁weapons - grade ▁u ran ium . ▁Phys ic ists ▁said ▁that ▁if ▁Iran ▁were ▁to ▁choose ▁to ▁develop ▁a ▁nuclear ▁weapon , ▁it ▁would ▁have ▁to ▁withdraw ▁from ▁the ▁International ▁N uc lear ▁Non - Pro l ifer ation ▁Tre aty ▁and ▁exp el ▁International ▁At omic ▁Energy ▁Agency