While Bahrain's justice minister was making the latest accusations against alleged enemies of the state, this time medical staff other officials were busy organising a patriotic blitz that encourages pledges of loyalty on Facebook and Twitter.

These are the parallel worlds of one of Washington's linchpin military allies in the Gulf.

On one side is a grinding campaign to break the spirits of Shiite-led opponents whose pro-reform uprising was smothered by martial law.

On the other: An expanding PR offensive to portray the Sunni monarchy as firmly in charge, and Bahrain as a firewall against Iranian influence in the nation that hosts the US Navy's 5th Fleet.

Bahrain's current spin shifting from state media to the web could appear as just more boosterism in a region where rulers are constantly bathed in state-sponsored praise.

But there is a distinct undercurrent in the island kingdom: pumping up its own rhetoric to match Iran's increasing barrage of criticism.

It serves as further recognition that Bahrain's crisis doubles as a window into the region's collective phobias the mutual mistrust of Sunni Arab leaders and Shiite powerhouse Iran as America effectively watches from the sidelines.

"So many of the Gulf's big issues are squeezed into this one tiny country," said Shadi Hamid, director of research at The Brookings Doha Center in Qatar.

Iran has relentlessly assailed Bahrain's rulers for crackdowns against the country's Shiite majority, which comprises 70 per cent of the population but is denied key roles in government or security affairs.

Tehran's statements took on an even harder edge after Bahrain's monarchy declared military rule and was aided in March by a Gulf force dominated by Iran's regional rival, Saudi Arabia.

The Gulf Arab sheiks and monarchs view Bahrain as a domino that cannot fall. Any gains by Bahrain's Shiites, in their minds, equates to a potential opening for greater Iranian footholds on Saudi Arabia's doorstep.

And Gulf leaders have set aside their traditional opaque and meandering political discourses to make their point, warning Iran to stop "meddling."

Last week in Abu Dhabi, Gulf interior ministers called Iran "provocative and irresponsible" after a senior military commander said the Gulf has always belonged to Iran.

On Thursday, Bahrain's chamber of commerce urged traders to shed Iranian investments and start a buy-Bahrain drive.

"This patriotic duty is dictated by our conscience, allegiance to the leadership and loyalty to Bahrain,' the group said.