By this weekend the impact of their shared Islamaphobia had triggered a violent backlash of worldwide protests in places as distant as Cairo, Khartoum and Sanaa.
At the core of the international controversy, which yesterday sparked new protests in Sydney, Paris and London, lay a crudely-crafted film that ridicules Muslims and the prophet Muhammed, alternately portraying him as a fraud, a womaniser and a child molester.
As the protests raged, the man identified as the key figure behind the film, Nakoula Basseley Nakoula, was taken in for questioning yesterday by police in California.
Most of the film, entitled Innocence Of Muslims, was shot in about two weeks inside the warehouse that serves as the offices of Media for Christ, a non-profit group that last year raised more than $1 million "to glow Jesus's light" to the world.
"I'd say this was the most unprofessional professional film I've ever worked on," said Eric Moers, who served as chief electrician for the production.
Moers is one of the few insiders who has spoken out about the film's creation and the individuals and organisations connected with a project that when it was released over the internet was regarded by many Muslims globally as deliberately hostile and provocative.
According to Moers, 90% of work on the film was done at the Media for Christ studios, located just off a highway next to a shopping mall in the sedate LA suburb of Duarte.
It was there that crew members received sheets with the scenes to be shot each day without ever seeing a full script. It was there, too, that Moers met a man called Sam Bacile – an apparent pseudonym US police have connected to Nakoula Basseley Nakoula, 55.
In 1997, Nakoula pleaded guilty to possession with intent to manufacture methamphetamine and was sentenced to a year in jail. In 2010, he pleaded guilty to bank and credit card fraud and was sentenced to 21 months in prison, to be followed by five years' probation.
Nakoula was freed in June 2011, and at least some production on Innocence Of Muslims was done that summer. The terms of his release included stipulations barring him from accessing the internet or assuming aliases without the approval of his probation officer. It was the breach of these conditions that led him to be taken in for questioning yesterday by California police.
Nakoula, however, is not the only person openly identified with the film.
Steve Klein, a California insurance salesman and Vietnam War veteran who has spent years protesting at mosques and espousing hatred of radical Muslims, acted as the film's promoter. He had a weekly show on Media for Christ's satellite network, The Way TV, and founded Courageous Christians United, which conducts protests outside abortion clinics, Mormon temples and mosques.
A number of US civil rights groups, including the Southern Poverty Law Centre, have been tracking Klein for several years and have labelled two of the organisations he is affiliated with as hate groups.
But Media for Christ appears the main conduit of the film that Klein was given the job of promoting.
Tax records for the charity do not identify any donors other than its president, Joseph Abdelmasih – a Coptic Christian originally from Egypt – who lent the organisation at least $30,000.
In all, Media for Christ is reported to have spent nearly $650,000 on "TV recording production" last year, though with no breakdown of costs it was unclear if any of that money was spent on Innocence Of Muslims.
What is certain, is that Abdelmasih has spoken out against radical Islam and participated in a protest against a proposal to build an Islamic cultural centre and "prayer space" near New York's World Trade Centre site.
Despite its poor production value, the film would have cost at least tens of thousands of dollars to make because of the equipment used and the professional actors and stage hands who were hired.
The permit, issued by Film LA, could have cost under $1,000, although details are not known because the document has been sealed at the request of federal law enforcement officials.
Eric Moers said he was paid with a cheque issued on the account of Abanob Basseley Nakoula, 20, the son of the purported film-maker. Moers also confirmed that one day's filming was spent at a movie ranch in Santa Clarita, and another filming at the home of the man he knew as Sam Bacile. Moers said most of the film was shot using a backdrop to simulate other locations and he insists there was no mention of the word "Muhammed" throughout the filming. Other actors have said references to Muhammed were dubbed after the film was shot and they had no idea the film would be so denigrating.
For many Muslims, any depiction of the prophet is blasphemous – caricatures deemed insulting in the past have provoked protests.
While the internet-released film may only have been 13 minutes long, its impact has been profoundly damaging to America's relations with the Arab and Islamic world. Extra troops have been sent to guard embassies after the US ambassador and three other Americans were killed in an attack on a US mission in Libya on Tuesday. The violence has since spread to Egypt, Lebanon, Tunisia, Sudan, Yemen and elsewhere.
But incendiary as the release of the film has undoubtedly been, there is growing evidence that it may have been used as a pretext by Islamic extremist and Jihadist groups to incite violence and create instability, especially in the Arab world's fledgling democracies.
The demonstration that engulfed the US embassy in Cairo was led by a group of Salafist activists. For the Salafists, this was a politically opportune moment, given their dissatisfaction with the success of their more moderate Islamist and secular rivals in the Muslim Brotherhood government of president Mohammed Morsi.
Indeed, the film was released at the beginning of June, but most Egyptians were unaware that the film existed until a talkshow host named Sheikh Khalid Abdullah devoted his two-hour programme to the video on September 8.
As a Muslim sheikh, Abdullah undoubtedly was offended by the film's contents. But he is also a Salafist, and there are suggestions he may have screened the film to incite chaos and complicate Egypt's newly-elected president's attempts to consolidate power.
In Libya, too, there are rival Islamist and political groups keen to challenge prime minister Abdurrahim el Keib and the secularist parties which are the backbone of the country's new government.
Where the Libyan scenario differs from Egypt, though, is that the attack on the US consulate in Benghazi was augmented by a well-armed Islamic militia. For some time now, attacks on foreign offices in the city have indicated a transnational ideology lies behind the motivation for such strikes and that militant Islamist groups may be re-emerging in Libya's east.
In short, there is undoubtedly much more to the violence and protests than simply outrage over a film. That said, in many parts of the world it is the flagrantly offensive nature of the video that is fuelling much of the anger.
Many US civil right groups say the film is the product of a well-financed vocal minority that has been fomenting anti-Muslim sentiment across the country since the September 11, 2001 terrorist attacks in New York and Washington, DC. Some experts say it's even more widespread.
"It's a transatlantic activity," said Jocelyne Cesari, a political scientist at the Johns Hopkins University School of Advanced International Studies in Washington, DC. "I have noticed the same topics, the same arguments, and the same figures actually circulating between Europe and the US."
Where most analysts agree, however, is that extremists on both sides are feeding off each others' negative stereotypes. It's a situation they say that can only get worse unless more moderate and reasoned voices prevail.