A drone strike killed Qasem Soleimani, head of Iranian Islamic Revolutionary Guard Corps (IRGC) Quds Force Unit in Baghdad. Qasem was very close to Iranian President Hassan Rouhani and Supreme Leader Ali Khamenei. This killing changed the equation between Iran and US. Ali Khamenei issued a fatwa against nuclear weapons before but now he feels time is ripe to withdraw the fatwa regarding nuclear option and start building the weapons.
Iran has mastered the technique to enrich uranium and they are ready to focus to build the weapon that would provide the freedom to exist as a sovereign nation.
World peace can only be possible if the fear of nuclear annihilation exist. The fear of nuclear option is the driving force for the true peace among human race. J. Robert Oppenheimer said after the first nuclear explosion,” Now I am become death, the destroyer of worlds”. Iran understand the depth of that statement and willing to mobilize for that option.