What is the difference?

Savak, the Shah's secret police 1957-1979

The Shah's brutal secret police force, Savak, formed under the guidance of CIA (the United States Central Intelligence Agency) in 1957 and personnel trained by Mossad (Israel's secret service), to directly control all facets of political life in Iran. Its main task was to suppress opposition to the Shah's government and keep the people's political and social knowledge as minimal as possible. Savak was notorious throughout Iran for its brutal methods.

The interrogation office was established with no limit of using horrific torture tools and techniques to break the arrested dissenters to talk in a matter of hours.

The censorship office was established to monitor journalists, literary figures and academics throughout the country. It took appropriate measures against those who fell out of the regime's line.

Universities, labor unions and peasant organizations, amongst others, were all subjected to intense surveillance by the Savak agents and paid informants. The agency was also active abroad, especially in monitoring Iranian students who publicly opposed the Shah's government.

Interrogation, torture and long term imprisonment by Savak for reading or possessing any forbidden books. The prohibited books were removed from the book-stores and libraries; even the Tozih-ol-Masael written by Ayatollah Rouhollah Khomeini was forbidden.

Over the years, Savak became a law unto itself, having legal authority to arrest, detain, brutally interrogate and torture suspected people indefinitely. Savak operated its own prisons in Tehran, such as Qezel-Qalaeh and Evin facilities and many suspected places throughout the country as well. Many of those activities were carried out without any institutional checks.

The monarchy was toppled in Iran on February 11th, 1979 (22nd day of Bahman 1357, Persian calendar). The Savak dissolved and then the Iranian people along with the political prisoners tasted the blossoms of freedom (Bahar-e Azadi) for a few months. The banned and forbidden newspapers, magazines and books started republishing until the religious dictatorship took place then Savama was created that resembled Savak in different forms of oppression.

---

Basij militia, Ayatollah's hanchmen 1979-????

Armed with sticks, motorbike chains, knives and axes, the more extreme members have long been used as shock troops by the regime to cow demonstrators with brutal displays of violence.

Mounted on motorbikes, the militia's standard strategy is to charge the crowd, one man driving and another riding pillion using a truncheon to lash out at stragglers.

They have also been sent to raid university campuses, breaking bones and smashing up dormitories.

The movement - its name is Persian for "mobilisation" - began as a sort of volunteer Dad's Army, comprising old men and young boys fired with zeal during the Iran-Iraq war.

Under the command of the Revolutionary Guards, they would charge blindly across minefields with plastic keys, symbolising the martyr's entry to paradise, strung round their necks.

Officially, the Basij today number some five million: but only a fraction of its cadres are thought to be active.

Many joined simply for the benefits membership confers: an easier route to university or increased chances of promotion in government jobs.

In contrast, the armed men prowling the streets last week are a hard core, totally committed to the Supreme Leader and President Mahmoud Ahmadinejad.

Many of them take a cue from Hajji Bakhshi, a grizzled veteran of the war with Iraq, who drives around Tehran in a bullet-riddled pick-up truck exhorting his followers to confront the forces of imperialism.

But this relish for violence and street bullying puts Basijis beyond the pale for most Iranians.

That was why protesters attacked a Basij outpost last Monday - provoking the militiamen into opening fire and killing seven people.

In the coming days, they are likely to once more play the bloodiest role in the struggle for the soul of Iran's Islamic republic.