If Iran sanctions fail, war may be inevitable: Peter Goodspeed
By imposing an embargo on Iranian oil exports and freezing assets of its central bank, EU members hope to cut so deeply into government revenues Tehran will agree to accept international safeguards on its nuclear program.

But the sanctions themselves may be the penultimate step before a possible military attack.

Iran says sanctions to fail, repeats Hormuz threat
Iranian politicians said on Tuesday they expected the European Union to backtrack on its oil embargo and repeated a threat to close the vital Strait of Hormuz shipping lane if the West succeeds in preventing Tehran from exporting crude.

Australia to follow EU lead in banning Iranian Oil
Australian Foreign Minister Rudd says Canberra will "undertake precisely the same parallel actions" as EU on Iran sanctions.