Egypt and Tunisia have overthrown repressive regimes.
Citizens in Syria, Yemen and other Middle East countries are demanding change. Yet in Iran, where a wave of 2009 demonstrations helped spark the movements we are now witnessing elsewhere in the Middle East, the populace is strangely silent.
What accounts for the relative quiet in Iran? The answer, at least in part, is that one of the great human rights tragedies of the modern era is under way in Iran.
From the moment the first protesters hit Tahrir Square in Cairo, Iran's leadership has cracked down hard, instituting a brutal campaign of terror against its own people.
The most gruesome manifestation of this repression has been a wave of public executions.
Since January, Iran has been on an execution binge. In February, the United Nations reported the rate of executions in Iran had increased threefold in 2011 over the previous year.
Amnesty International reported that Iran is the only country this year known to have executed juvenile offenders, a violation of international law.
Although exact numbers are difficult to come by, it is now estimated by human rights organizations that more than 140 people have been executed in Iran so far this year, a rate that, if continued, would push the number far past the total for 2010.
What is perhaps most disturbing, and provides clear evidence of Iran's effort to intimidate and terrorise its own population, is the growing number of executions in Iran taking place in public.
Amnesty International estimates that as many as 13 people had been hanged in public by the end of April, compared to a total 14 in all of 2010.
In a number of instances, those executed have been left hanging high in the air on construction cranes for all to see.
As an Amnesty official noted in an April report: "It is deeply disturbing that despite a moratorium on public executions ordered in 2008, the Iranian authorities are once again seeking to intimidate people by such spectacles, which not only dehumanise the victim but brutalise those who witness it."
Only a month later, Iran Human Rights, a leading human rights group, reported the regime put 54 people to death in May, with 15 of the executions carried out publicly.
The international community needs to call for an end to this kind of barbarism and highlight more broadly the deteriorating human rights situation in Iran.
In response to Iran's brazen attempts to intimidate and terrorise its own people, United Against Nuclear Iran has launched a Cranes Campaign. The goal is to educate crane manufacturers worldwide about the Iranian regime's clear misuse of their products and how such use can tarnish their brand image.
The proper response to that from the international community must be resolute and firm: Iran's behaviour is unacceptable and far outside the boundaries of civilised society.
Civilised nations, and the businesses based in them, should never be complicit.
