The BBC ran an article under the title
"'Provocative' Clinton angers Iran"
http://news.bbc.co.uk/2/hi/middle_east/7376741.stm in which it reported that Iran complained to the UN about Hillary Clinton's statement that the US could "totally obliterate" Iran if it attacked Israel.
Tehran, which insists its nuclear programme is solely for power generation, denounced her words as "provocative and irresponsible".
It said the remarks were "a flagrant violation" of the UN Charter.
Now, it's obviously a threat. But all that Iran has to do to avoid invoking this threat is to refrain from attacking Israel. What's more, it's obvious from the context of the threat that Hillary meant directly attacking Israel or attacking Israel with weapons of mass destruction.
So why would Iran consider this threat pertinent and mortal? This only makes sense if Iran is, in fact, building nuclear weapons and planning to use them against Israel.
Careful, Iran, you're admitting things by implication which contradict your claim to be a rational and peaceful Power.