Name the last country Mullahs in Tehran attacked or threatened to attack .
Let's start from the beginning.
The Late Ayatullah Ruhullah Khumeini annoucned right after gaining power, that he would export the revolution to other Arab and muslim states. This led to scrambling by neighbouring arab countries, who persuaded SAddam Hussein to attack Iran in a pre-emptive strike, which led to the 10 year war betweeen the two countries.
Iran funded and trained extremist groups in countries such as Egypt, Pakistan, Lebanon, in order to propogate an extreme version of Shia Islamic Ideology, which led to the creation in Pakistan in 1980 of Tahreek Nifaz Fiqqah Jafria, which won fame and notoriety by surrounding Islamabad, forcing the government to accept their demands among which was exempting themselves from the zakat ordinance brought in by Zia ul Haq. The easiest way to avoide compulsory zakat deductions from employees salaries and bank accounts, was then to proclaim oneself as Ahle Tashee. One must remember that the creation of Tehreek Jafria preceded the creation of the equally extreme Sipah Sahaba, by several years, and was in fact one of the catalysts for its emergence.
This same Tehreek jafria later morphosised into the Sipah Muhammad terrorist group that was responsible for many tit for tat killlings during the shia sunni clashes of the late 80s and 90s.
In Afghanistan, the Iranians meddled by supporting the hizbe wahdat militia, which turned against the other mujahideen during the late 80s, due to sectarian differences. The Iranians were also responsible for prologning the suffering in AFghanistan by supporting the likes of General Dostum, Rabbani, and later on even Ahmad Shah Masood, just to stop Pakistan from gaining a friendly govt. One may note that these were the exact people that the Americans also chose to support when they 'invaded' Afghanistan, so Iran and America have more in common than we may think.
The Iranians also supported terrorist groups seeking to overthrow the govt. in Bahrain, as the regime is headed bya Sunni family, while hte majority of Bahrainis are of hte Shia persusasion. The protracted bombing campaign, and loss of life in Bahrain is a stain on the conscience of Iran.
Aggressive proseltyzing in most muslim countries by Iranian "Cultural Centers" which published books criticising the companions and wives of the Prophet mUhammad, sought to sow discord among peace loving Shia and Sunnis.
The attack on the Kaba, during the hajj, when Iranian pilgrims brought weapons into the Haram, encouraged other pilgrims to join them, some claiming that the Imam Mehdi had arrived and subsequenty went on to try to kidnap the entire congregation of hajj pilgrims in the vicinity of the Haram. A small bloodbath ensued, and Iranians were forbidden to perform Hajj for a number of years. This happened just after the revolution in Iran.
Iran has tried to meddle in the affairs of most muslim countries in the region, solely on the basis of religious sectarianism, which has brought about a reaction in sunni anti shia extremism that is seen tday.
Iran has a lot to answer for.