WASHINGTON — First lady Melania Trump has all but vanished.
She hasn't been seen with President Donald Trump at a public event since May 10, four days before she underwent a procedure for a kidney problem. She won't be at her husband's side for the G-7 economic meeting in Quebec City later this week, and she's not going to Singapore for his historic nuclear disarmament summit with North Korean leader Kim Jong Un.
The first lady is expected to join the president at an event for Gold Star military families at the White House on Monday — but it's closed to the press.
All of this has touched off a set of conspiracy theories, and a miniature culture war, over Mrs. Trump's whereabouts, her physical condition and the status of her relationship with the president. And it's raised the question of the significance of the first lady to the president's state of mind and the functioning of the White House.
Amid the speculation, Melania Trump's account tweeted last week.
Not only did that not work to quell the chatter, but the language of the tweet — which mirrored the president's rhetorical tics — kicked off a new round of speculation about whether it had been written by him or someone who writes for him.
The reason Mrs. Trump has been out of the public eye lately — and won't travel to Quebec or Singapore — could be as simple as her recovery from the procedure and a desire to avoid blood clotting on flights.
But for the left, there's a lot of appeal to the idea that the first lady has essentially been held hostage by her husband's presidency — unable to get away from him or the public spotlight — while he embarrasses her.
Trump acknowledged earlier this year that he had compensated lawyer Michael Cohen for a hush payment to the adult film actress and director who says she had an affair with Trump while he was married to Mrs. Trump, who has repeatedly rebuffed her husband's attempts to hold her hand in public.
She would hardly be the only first lady to feel trapped by the position.
As Kate Andersen Brower writes in her book "First Women: The Grace and Power of America's Modern First Ladies," it's been a common sentiment since the founding of the nation.
"Martha Washington called herself a 'state prisoner,'" Brower writes. "Jacqueline Kennedy proclaimed: 'The one thing I do not want to be called is 'First Lady.' It sounds like a saddle horse.' And Michelle Obama says that living in the White House is like living in a 'really nice prison.'"
Modern first ladies have typically taken on a public policy role within a position that is undefined by the Constitution or federal law. But they have always been influential with their husbands — and often with lawmakers, administration officials and foreign dignitaries.
So the disappearance of a first lady means the White House is playing without a full roster for now, which is more meaningful in some situations than in others.
Anita McBride, who was chief of staff to Laura Bush, said there's a difference between the G-7, a conference that Melania Trump attended last year in Italy, and the nuclear talks.
"I don't see any reason why she should or would need to go to Singapore for the North Korea summit," she said. "It would seem premature to me that our two countries are even at that point of a relationship or friendship that requires building bridges through and with the spouse. North Korea has a long way to go there."
On the other hand, McBride said, there are opportunities for the first lady to advance American interests at an event like the G-7, where longstanding relationships between world leaders and their families develop.
"There is no requirement that a spouse attend the global meetings, and it is certainly only up to her what goes on her schedule, but having said that, it does make a difference to have the wife of the American president at these events," she said. "Besides the opportunity to keep building relationships with the other spouses, it's helpful in building relationships with the leaders too."
At a time when he's slapped allies with new tariffs, Trump could use all the help he can get on that score. But for the moment, one of his chief diplomatic partners is sticking to the sidelines.
CORRECTION (June 4, 2018, 2:23 p.m., ET): An earlier version of this article misspelled the name of the author of "First Women: The Grace and Power of America’s Modern First Ladies." She is Kate Andersen Brower, not Anderson Brower.