They did not unreasonably retaliate their enemies with an equivalent intensity of terror but intellectuallly they fought it in the UN even if they knew they will get nothing from this institution which was dominated and influenced by US of A and Israel.
Now that Iran is able to stand against their adversaries in the field of Nuclear Technology, though Iran insist it is only for civilian purposes yet Iran's adversaries insist it is for the purpose of developing Nuclear weapons. And also Iran is flexing her muscles in gaining more friends and allies by projecting their image as a real peacemaker and advocating equal social justice asides from their scientific achievements. These I think are the real source of fear for Iran's fiercest adversaries Israel and US of A.
Meanwhile, just like me, you and the for world who long for genuine peace untainted with personal interests, I like you to watch this documentary video about Iran...
IRAN Documentary Yesterday and Today : Rick Steves - YouTube