President Barack Obama travels to Saudi Arabia this week for talks with the most powerful nation on the Arabian Peninsula, the hosts, but the American president also plans to meet with other regional officials from the Gulf Cooperation Council.

The GCC includes the UAE, and Obama may for a moment wonder why the Emirati president is not there.

Which strikes at the heart of the curious case of the UAE’s unseen president.

Sheikh Khalifa bin Zayed, only the second leader of a country founded in 1971, has not been seen in public since December 2013.

It was on Saturday, January 25, 2014, that the state news agency WAM tersely reported that Sheikh Khalifa had suffered a stroke and had undergone surgery.

Obama may recall the “best wishes to Sheikh Khalifa” message, under his signature, that was forwarded in early February 2014 from John Kerry, the U.S. secretary of state, to Sheikh Abdullah bin Zayed, the UAE’s foreign minister — and one of Sheikh Khalifa’s half-brothers.

At about the same time, Sheikh Mohammed bin Zayed, the crown prince of Abu Dhabi (and next in line for the presidency), also a half-brother of Sheikh Khalifa, tweeted that UAE citizens had nothing to worry about.

Part of that tweet attributed to Sheikh Mohammed the comment: “The leadership of the UAE keeps nothing from its people and maintains full transparency” — as he dismissed rumors about Sheikh Khalifa’s health and questions about the same.

Inside the country, it is considered bad form to speculate aloud about the condition of Sheikh Khalifa … even though almost everyone, from Emiratis to expats, does so, in private. It is natural, after all, to wonder who is in charge.

In July of 2014, the crown prince issued another statement again discouraging speculation on social media.

In the meantime, occasional messages or proclamation are issued under the name of Sheikh Khalifa. In January of last year he was said to have sent condolences to Saudi Arabia on the death of King Abdullah.

In March of last year, Sheikh Khalifa was said to have sent condolences to Singapore on the death of former prime minister Lee Kuan Yew.

The last public event involving Sheikh Khalifa, if we go by the website of The National, the government-owned English-language newspaper, was in early December 2013, when WAM released a photo of the president with Iran’s foreign minister.

Since then, the government has not been much help in shedding light on the condition of the president, who was born in 1948 and has been thought to be in failing health even before the 2014 stroke. He had been out of the country more than once to receive medical treatment; one occasion was noted when he returned from a medical trip to Switzerland in 2010.

If the UAE were a bigger player on the global stage, presumably international media would ask questions about its president. Instead, whether Sheikh Khalifa is dead, alive or incapacitated … people inside (as well as outside) the country are left to guess.

It is not as if the UAE is suffering from a leadership vacuum. Sheikh Mohammed, the crown prince, appears to be in charge of foreign policy, and Dubai’s Sheikh Mohammed bin Rashid, the vice president, is a leading voice in domestic affairs. Both appear to be popular leaders.

Still, Obama may ponder, this week, the absence of the UAE’s president.