MICHELLE Obama was not doing anything outrageous by choosing to forgo a headscarf when she and Barack Obama visited Saudi Arabia to pay their respects following King Abdullah's death.

There was no big, etiquette-flouting statement; no defiant fingers-up to the women-oppressing Saudi establishment. In leaving her hair uncovered, she was just doing what many Western women - including Laura Bush and Hillary Clinton - had done before. Yet, it's a sign of current cultural volatility that Michelle Obama's uncovered hair became a big story last week.

It began, apparently, with 2500 tweets - not all of them by Saudis and not all of them serious - expressing offence at her lack of head covering. The response was reported by news website Ahram Online, then The Washington Post, followed by the rest of the world. Around the same time came "Blurgate": when Saudi television was accused of blurring out the US First Lady's head because it was not covered. This turned out not to be true, but the story had become unstoppable. Some commentators declared Michelle Obama brave and courageous; others, disrespectful or offensive

Then we learned the reality: that Western women living in Saudi Arabia are not required to cover their hair, though, as Muslim writer Hadiya Abdelrahman put it, "this contrasts strongly to women of Saudi, Pakistani, and other brown backgrounds, whose choices are regulated and controlled by the US state sponsored royal family". Even Saudis, however, will not be arrested for baring their hair, though they may be hassled by the religious police.

So we know now that Michelle Obama wasn't really being brave. It was easy for her not to wear a headscarf. Easier, in fact, than wearing one, which would have been the real breaking of convention, and, as many have said, probably have led to critics accusing the Obamas of being Muslims. There was, in fact, nothing offensive in her dress or behaviour: she wore a very respectful long-sleeved coat and trousers; below the neck, the only part of her body uncovered was her hands.

The story does, however, expose Western assumptions about the way restrictions work in the Islamic world and Saudi Arabia in particular. It also reveals how ready we are, in these fevered times, to believe something is an offence.

Perhaps this story was always bound to get blown out of proportion - it involved the hijab, now one of the most potent and controversial symbols of our times. But also, it involved, the First Lady, whose office is an anachronistic, empty and symbolic one. What is she even there for, we might ask. Officially she's meant to be a hostess and advisor - but mostly, it seems, she is there to be read by the public as part of the image of the presidency. Since she lacks a proper political role, she is constantly examined for what kind of statement she's making, whether sartorial, political, or ethical. She goes to Riyadh and does and says nothing, yet we invest the visit with meaning.

But the story also reveals a desire lurking in Western culture for the Obamas to sock it to the Saudis on human rights, particularly regarding women. That didn't happen last week. Speaking before the trip, Barack Obama acknowledged that he would not be raising US concerns about Saudi Arabia's treatment of the blogger, Raid Badawi, who was sentenced to 10 years in prison and 1000 lashes for insulting Islam. He said he was "just paying respects to King Abdullah, who in his own fashion presented some modest reform efforts within the kingdom". Indeed, anyone wishing for any critical statement of the Saudi regime would not have found it in the Presidential visit, nor elsewhere among global leaders. The flag outside Westminster Abbey flew at half-mast. David Cameron said he was "deeply saddened" by the Saudi King's death.

Even if Michelle Obama's uncovered hair had been meant as a criticism of Saudi human rights, would that have been helpful? I doubt it. Women who want to be freed of the veil are not helped by someone from outside their culture. As commentator Hadiya Abdelrahman wrote, for these women, Michelle Obama "will serve as a stark reminder of what the West embodies to the average citizen: an undisputed access to power of choice that a Saudi woman does not have ... She only tells Muslim women what they already knew: that some women stand above them".

So, we should be wary of assuming that an easy symbolic act by one privileged woman of relative freedom can make any real difference. What helps the Saudi women who want those freedoms, is other Saudi women: women like Manal Sharif, who started the Women2Drive movement in defiance of the fact women are not allowed to drive. It's other Muslim men and women who challenge such restrictions. And most importantly, it's reforms, which Barak Obama, and other world leaders, should press more strongly for.

A glimpse of the First Lady's hair, blurred or not, will change nothing.