Answer:
The possession of Weapon of mass destruction by Iran
Explanation:
USA and allies are against nuclear weapon powered Iran and has accused Iran of stock piling uranium,learning designs and capability of diverting civilian nuclear program to manufacture of WMD.
Their evidence base on the followings:
a. Concealment of nuclear development program
b. Support to terrorist groups like Hamas and Hezbollah
c. Distortion in geopolitics of the middle east.
d. General perception that WMD might fall into wrong hands or terrorists.
The evidence against Iran is weak, because many countries, especially China and Russia believes that Iran lacks the capability to produce nuclear war head. However, they opposed any country in region having nuclear weapon. They believe that Iran has power to produce nuclear energy for peaceful purpose.