According to Steven Erlanger article; The European Union will impose economic sanction against Iran if Iran don't backup on its nuclear weapons program. The European Union wanted Iran to co-operate with the United Nation. EU will prohibit trade with Iran, and freeze transactions with Iran's central bank. French officials wanted to avoid military action against Irena and also Israeli attack on Irena. The EU believes the sanction will bring Irena to negation table. On other said the president of Iran said," enriching uranium for peaceful use not for military intent". 
In my opinion, economic sanction is better way instead of military action. War can be very costly. This sanction can be hard for Iran economic and also will affect some of Europe Union countries. One of this countries is Greece who dependent on Iranian oil. I think the sanction against Iran will affect the price of oil around the world.