pasban - why do iranians not have the peace with arabs in todays world - what is the basis for this rivalry? (in your opinion?)
Actually, it's very one-sided to saw that Iran is not at peace with Arabs for the same could be argued in reverse as well. Also, there are many Arabs and Arab groups which are very much in harmony with Iran-- as a small example we can point out to the Iranian Arab community centered around southern Iran where they form a majority.
Anyhow briefly,
Prior to the Islamic revolution, the puppet Shah of Iran, closely allied himself to the state of Israel despite much angst at it at home. This was more pronounced during the Arab-Israeli wars. This then kept a very different balance in the Middle East with the Shah and Israel being the primary allies within the region. For it's part Israel followed a policy which was often termed an alliance of the periphery, seeking close ties with outlying states of the region to offset it's position within the region. This brought about ties with Iran and Turkey. The Shah's apparent near ethnic based chauvinism (though, himself not being Persian) was matched at the time by a rise in pan-Arabism which ultimately came to it's full brunt during the Arab-Israeli conflicts and later the Iran-Iraq war. This as such, created much tension. In order to maintain the fragile balance at the other end of the spectrum, the US also actively supported selected Arab states. The geo-politics were played out both using an ethnic and religious basis from time to time depending on individual circumstance.
The coming on the Islamic revolution turned that balance upside down. The loss of Iran from a set group changed the paradigm completely. Having toppled a monarch, the revolutionaries were ardently anti-monarchy, which they termed as being anti-imperialism, and were against foreign intervention in the region. Also, given the Islamic backdrop of the revolution, they were compelled by religious principles. This became of great concern not only to external players but powers within the region around the Persian Gulf where the key Arab states were all under monarchies themselves. This would change the politics of the region entirely. The monarchical Arab states were most concerned and this culminated in their heavy support of chauvinistic and expansionist Saddam Hussein. This only created further rift.
Concerning the mid-90s and beyond, I see an imbalance. For it's part since the mid-90s Iran has been attempting to formalize relations further. This led to to development of closer ties with Syria, Lebanon and most recently Iraq, which is an area still developing. Also, Iran sent a delegation to Saudi Arabia, Qatar, Kuwait, Bahrain and so forth. The response in my view hasn't been equal. Also, Iranian clergy has been releasing statements and verdicts to down-play the religious divide. At it's core, the principles of the revolution stand in stark contrast to the ruling elements in these said states-- monarchies with the addition of being closely tied to the US and it's allies. This also gets played in a sectarian sense, because apart from Lebanon, Yemen and Iran, the remainder of the Arab Shi'a population of the Middle-East resides bordering the Persian Gulf region with Iran at the opposite shore. States like Qatar, Iraq, Bahrain and Kuwait have Shi'a majorities and the Shi'a minority of larger states like Saudi Arabia are also based in the eastern end of the country. This has kept a thought of an Iranian inspired Shi'a uprising or revolution in the mindset of the ruling elite who all belong to a different religious school. With the coming of an Islamic revolution in Iran, seen as a Shi'a revolution, this fear was felt to be more substantiated. Moreover, this very region is the oil producing basin of the world. Understandably, as such, there are numerous vested interests involved.
