Wearing silk satin crepe dress with black skirt and white bodice by Isabel Toledo, did First Lady Michelle Obama feel pressure to cover her arms — reportedly a black Azzedine Alaia cardigan — when she met Queen Elizabeth II at Buckingham Palace yesterday?

If Jackie Kennedy could go sleeveless all those many years ago to meet the Queen, what happened that our brave, 21st-century First Lady covered up? Inquiring fashion theorists want to know …

In Washington, the First Lady has pretty much stopped baring her well-toned arms ever since they threatened to steal the spotlight from the White House’s economic policies. But in London, after meeting the Queen, she was sleeveless in her Toledo outfit posing for photographs with President Obama on their way into a Jamie Oliver-prepared dinner at Downing Street last night.

Pressure? Protocol? Frightened of the Queen? Well, according to a close fashion-world confidante of the First Lady, the deciding factor on the covering cardigan was simple: It is cold inside Buckingham Palace! To save British taxpayers extra expense, the Queen keeps the heat way low — the temperature today in London was a brisk 54 degrees — and the palace is very drafty. Goose bumps or cardigan, Mrs. Obama? Cardigan, of course.

And then there is the most interesting cardigan twist: It is made by a French designer, Azzedine Alaia. So what do you think? Is there some fashion diplomacy happening here? Since Mrs. Obama was expected to wave the flag of American designers exclusively in her official wear, this bit of bonjour to Paris — if indeed the cardigan is Azzedine, and I do trust my source 95 percent of the time — could be interpreted as a diplomatic gesture to the French people and President Nicolas Sarkozy, especially, who has threatened to walk out of the G-20 Summit if his demands for new, tighter financial regulations are not met.